diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1979177f..d06b712f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,51 @@
+## 1.77.3
+
+### Dart API
+
+* `Deprecation.duplicateVariableFlags` has been deprecated and replaced with
+  `Deprecation.duplicateVarFlags` to make it consistent with the
+  `duplicate-var-flags` name used on the command line and in the JS API.
+
+## 1.77.2
+
+* Don't emit deprecation warnings for functions and mixins beginning with `__`.
+
+* Allow user-defined functions whose names begin with `_` and otherwise look
+  like vendor-prefixed functions with special CSS syntax.
+
+### Command-Line Interface
+
+* Properly handle the `--silence-deprecation` flag.
+
+* Handle the `--fatal-deprecation` and `--future-deprecation` flags for
+  `--interactive` mode.
+
+## 1.77.1
+
+* Fix a crash that could come up with importers in certain contexts.
+
+## 1.77.0
+
+* *Don't* throw errors for at-rules in keyframe blocks.
+
+## 1.76.0
+
+* Throw errors for misplaced statements in keyframe blocks.
+
+* Mixins and functions whose names begin with `--` are now deprecated for
+  forwards-compatibility with the in-progress CSS functions and mixins spec.
+  This deprecation is named `css-function-mixin`.
+
+## 1.75.0
+
+* Fix a bug in which stylesheet canonicalization could be cached incorrectly
+  when custom importers or the Node.js package importer made decisions based on
+  the URL of the containing stylesheet.
+
+### JS API
+
+* Allow `importer` to be passed without `url` in `StringOptionsWithImporter`.
+
 ## 1.74.1
 
 * No user-visible changes.
diff --git a/lib/index.ts b/lib/index.ts
index 96ce209b..e148d962 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -40,8 +40,8 @@ export {
   Deprecation,
   DeprecationOrId,
   DeprecationStatus,
-  Version,
 } from './src/deprecations';
+export {Version} from './src/version';
 export {render, renderSync} from './src/legacy';
 
 export const info = `sass-embedded\t${pkg.version}`;
diff --git a/lib/src/canonicalize-context.ts b/lib/src/canonicalize-context.ts
new file mode 100644
index 00000000..46111a8a
--- /dev/null
+++ b/lib/src/canonicalize-context.ts
@@ -0,0 +1,32 @@
+// Copyright 2024 Google LLC. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+export class CanonicalizeContext {
+  readonly fromImport: boolean;
+
+  private readonly _containingUrl: URL | null;
+
+  get containingUrl(): URL | null {
+    this._containingUrlAccessed = true;
+    return this._containingUrl;
+  }
+
+  private _containingUrlAccessed = false;
+
+  /**
+   * Whether the `containingUrl` getter has been accessed.
+   *
+   * This is marked as public so that the importer registry can access it, but
+   * it's not part of the package's public API and should not be accessed by
+   * user code. It may be renamed or removed without warning in the future.
+   */
+  get containingUrlAccessed(): boolean {
+    return this._containingUrlAccessed;
+  }
+
+  constructor(containingUrl: URL | null, fromImport: boolean) {
+    this._containingUrl = containingUrl;
+    this.fromImport = fromImport;
+  }
+}
diff --git a/lib/src/deprecations.ts b/lib/src/deprecations.ts
index f69284cc..e30527c4 100644
--- a/lib/src/deprecations.ts
+++ b/lib/src/deprecations.ts
@@ -2,33 +2,17 @@
 // MIT-style license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
-import * as api from './vendor/sass';
+import {deprecations} from './vendor/deprecations';
+import {Deprecation, DeprecationOrId} from './vendor/sass';
+import {Version} from './version';
 
+export {deprecations} from './vendor/deprecations';
 export {Deprecation, DeprecationOrId, DeprecationStatus} from './vendor/sass';
 
-export class Version implements api.Version {
-  constructor(
-    readonly major: number,
-    readonly minor: number,
-    readonly patch: number
-  ) {}
-  static parse(version: string): Version {
-    const match = version.match(/^(\d+)\.(\d+)\.(\d+)$/);
-    if (match === null) {
-      throw new Error(`Invalid version ${version}`);
-    }
-    return new Version(
-      parseInt(match[1]),
-      parseInt(match[2]),
-      parseInt(match[3])
-    );
-  }
-}
-
 /**
  * Returns whether the given deprecation was active in the given version.
  */
-function isActiveIn(deprecation: api.Deprecation, version: Version) {
+function isActiveIn(deprecation: Deprecation, version: Version) {
   const deprecatedIn = deprecation.deprecatedIn;
   if (deprecation.status !== 'active' || !deprecatedIn) return false;
   if (version.major > deprecatedIn.major) return true;
@@ -43,7 +27,7 @@ function isActiveIn(deprecation: api.Deprecation, version: Version) {
  * that's ready to include in a CompileRequest.
  */
 export function getDeprecationIds(
-  arr: (api.DeprecationOrId | Version)[]
+  arr: (DeprecationOrId | Version)[]
 ): string[] {
   return arr.flatMap(item => {
     if (item instanceof Version) {
@@ -56,132 +40,3 @@ export function getDeprecationIds(
     return item.id;
   });
 }
-
-export const deprecations: typeof api.deprecations = {
-  'call-string': {
-    id: 'call-string',
-    status: 'active',
-    deprecatedIn: new Version(0, 0, 0),
-    obsoleteIn: null,
-    description: 'Passing a string directly to meta.call().',
-  },
-  elseif: {
-    id: 'elseif',
-    status: 'active',
-    deprecatedIn: new Version(1, 3, 2),
-    obsoleteIn: null,
-    description: '@elseif.',
-  },
-  'moz-document': {
-    id: 'moz-document',
-    status: 'active',
-    deprecatedIn: new Version(1, 7, 2),
-    obsoleteIn: null,
-    description: '@-moz-document.',
-  },
-  'relative-canonical': {
-    id: 'relative-canonical',
-    status: 'active',
-    deprecatedIn: new Version(1, 14, 2),
-    obsoleteIn: null,
-  },
-  'new-global': {
-    id: 'new-global',
-    status: 'active',
-    deprecatedIn: new Version(1, 17, 2),
-    obsoleteIn: null,
-    description: 'Declaring new variables with !global.',
-  },
-  'color-module-compat': {
-    id: 'color-module-compat',
-    status: 'active',
-    deprecatedIn: new Version(1, 23, 0),
-    obsoleteIn: null,
-    description:
-      'Using color module functions in place of plain CSS functions.',
-  },
-  'slash-div': {
-    id: 'slash-div',
-    status: 'active',
-    deprecatedIn: new Version(1, 33, 0),
-    obsoleteIn: null,
-    description: '/ operator for division.',
-  },
-  'bogus-combinators': {
-    id: 'bogus-combinators',
-    status: 'active',
-    deprecatedIn: new Version(1, 54, 0),
-    obsoleteIn: null,
-    description: 'Leading, trailing, and repeated combinators.',
-  },
-  'strict-unary': {
-    id: 'strict-unary',
-    status: 'active',
-    deprecatedIn: new Version(1, 55, 0),
-    obsoleteIn: null,
-    description: 'Ambiguous + and - operators.',
-  },
-  'function-units': {
-    id: 'function-units',
-    status: 'active',
-    deprecatedIn: new Version(1, 56, 0),
-    obsoleteIn: null,
-    description: 'Passing invalid units to built-in functions.',
-  },
-  'duplicate-var-flags': {
-    id: 'duplicate-var-flags',
-    status: 'active',
-    deprecatedIn: new Version(1, 62, 0),
-    obsoleteIn: null,
-    description: 'Using !default or !global multiple times for one variable.',
-  },
-  'null-alpha': {
-    id: 'null-alpha',
-    status: 'active',
-    deprecatedIn: new Version(1, 62, 3),
-    obsoleteIn: null,
-    description: 'Passing null as alpha in the JS API.',
-  },
-  'abs-percent': {
-    id: 'abs-percent',
-    status: 'active',
-    deprecatedIn: new Version(1, 65, 0),
-    obsoleteIn: null,
-    description: 'Passing percentages to the Sass abs() function.',
-  },
-  'fs-importer-cwd': {
-    id: 'fs-importer-cwd',
-    status: 'active',
-    deprecatedIn: new Version(1, 73, 0),
-    obsoleteIn: null,
-    description:
-      'Using the current working directory as an implicit load path.',
-  },
-  'color-4-api': {
-    id: 'color-4-api',
-    status: 'active',
-    deprecatedIn: new Version(1, 76, 0),
-    obsoleteIn: null,
-    description: 'Methods of interacting with legacy SassColors.',
-  },
-  'color-functions': {
-    id: 'color-functions',
-    status: 'active',
-    deprecatedIn: new Version(1, 76, 0),
-    obsoleteIn: null,
-    description: 'Using global Sass color functions.',
-  },
-  import: {
-    id: 'import',
-    status: 'future',
-    deprecatedIn: null,
-    obsoleteIn: null,
-    description: '@import rules.',
-  },
-  'user-authored': {
-    id: 'user-authored',
-    status: 'user',
-    deprecatedIn: null,
-    obsoleteIn: null,
-  },
-};
diff --git a/lib/src/importer-registry.ts b/lib/src/importer-registry.ts
index 9a1cb337..749a912b 100644
--- a/lib/src/importer-registry.ts
+++ b/lib/src/importer-registry.ts
@@ -7,6 +7,7 @@ import * as p from 'path';
 import {URL} from 'url';
 import {inspect} from 'util';
 
+import {CanonicalizeContext} from './canonicalize-context';
 import * as utils from './utils';
 import {FileImporter, Importer, Options} from './vendor/sass';
 import * as proto from './vendor/embedded_sass_pb';
@@ -115,21 +116,22 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
       throw utils.compilerError('Unknown CanonicalizeRequest.importer_id');
     }
 
+    const canonicalizeContext = new CanonicalizeContext(
+      request.containingUrl ? new URL(request.containingUrl) : null,
+      request.fromImport
+    );
+
     return catchOr(
       () => {
         return thenOr(
-          importer.canonicalize(request.url, {
-            fromImport: request.fromImport,
-            containingUrl: request.containingUrl
-              ? new URL(request.containingUrl)
-              : null,
-          }),
+          importer.canonicalize(request.url, canonicalizeContext),
           url =>
             new proto.InboundMessage_CanonicalizeResponse({
               result:
                 url === null
                   ? {case: undefined}
                   : {case: 'url', value: url.toString()},
+              containingUrlUnused: !canonicalizeContext.containingUrlAccessed,
             })
         );
       },
@@ -197,17 +199,21 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
       throw utils.compilerError('Unknown FileImportRequest.importer_id');
     }
 
+    const canonicalizeContext = new CanonicalizeContext(
+      request.containingUrl ? new URL(request.containingUrl) : null,
+      request.fromImport
+    );
+
     return catchOr(
       () => {
         return thenOr(
-          importer.findFileUrl(request.url, {
-            fromImport: request.fromImport,
-            containingUrl: request.containingUrl
-              ? new URL(request.containingUrl)
-              : null,
-          }),
+          importer.findFileUrl(request.url, canonicalizeContext),
           url => {
-            if (!url) return new proto.InboundMessage_FileImportResponse();
+            if (!url) {
+              return new proto.InboundMessage_FileImportResponse({
+                containingUrlUnused: !canonicalizeContext.containingUrlAccessed,
+              });
+            }
             if (url.protocol !== 'file:') {
               throw (
                 `FileImporter ${inspect(importer)} returned non-file: URL ` +
@@ -216,6 +222,7 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
             }
             return new proto.InboundMessage_FileImportResponse({
               result: {case: 'fileUrl', value: url.toString()},
+              containingUrlUnused: !canonicalizeContext.containingUrlAccessed,
             });
           }
         );
diff --git a/lib/src/legacy/importer.ts b/lib/src/legacy/importer.ts
index 97ef9117..5977a3d5 100644
--- a/lib/src/legacy/importer.ts
+++ b/lib/src/legacy/importer.ts
@@ -86,10 +86,34 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
 
   canonicalize(
     url: string,
-    options: {fromImport: boolean}
+    options: {fromImport: boolean; containingUrl: URL | null}
   ): PromiseOr<URL | null, sync> {
     if (url.startsWith(endOfLoadProtocol)) return new URL(url);
 
+    // Emulate a base importer instead of using a real base importer,
+    // because we want to mark containingUrl as used, which is impossible
+    // in a real base importer.
+    if (options.containingUrl !== null) {
+      try {
+        const absoluteUrl = new URL(url, options.containingUrl).toString();
+        const resolved = this.canonicalize(absoluteUrl, {
+          fromImport: options.fromImport,
+          containingUrl: null,
+        });
+        if (resolved !== null) return resolved;
+      } catch (error: unknown) {
+        if (
+          error instanceof TypeError &&
+          isErrnoException(error) &&
+          error.code === 'ERR_INVALID_URL'
+        ) {
+          // ignore
+        } else {
+          throw error;
+        }
+      }
+    }
+
     if (
       url.startsWith(legacyImporterProtocolPrefix) ||
       url.startsWith(legacyImporterProtocol)
diff --git a/lib/src/legacy/index.ts b/lib/src/legacy/index.ts
index 404937cf..d7543e35 100644
--- a/lib/src/legacy/index.ts
+++ b/lib/src/legacy/index.ts
@@ -184,11 +184,20 @@ function convertStringOptions<sync extends 'sync' | 'async'>(
 ): StringOptions<sync> & {legacy: true} {
   const modernOptions = convertOptions(options, sync);
 
-  // Find the first non-NodePackageImporter to pass as legacy `importer` option.
-  // NodePackageImporter will be passed in `modernOptions.importers`.
-  const importer = modernOptions.importers?.find(
-    _importer => !(_importer instanceof NodePackageImporter)
-  ) as Importer<sync> | FileImporter<sync>;
+  // Use a no-op base importer, because the LegacyImporterWrapper will emulate
+  // the base importer by itself in order to mark containingUrl as accessed.
+  const importer = modernOptions.importers?.some(
+    importer => importer instanceof LegacyImporterWrapper
+  )
+    ? {
+        canonicalize() {
+          return null;
+        },
+        load() {
+          return null;
+        },
+      }
+    : undefined;
 
   return {
     ...modernOptions,
diff --git a/lib/src/value/argument-list.ts b/lib/src/value/argument-list.ts
index e5c41cb1..b898796a 100644
--- a/lib/src/value/argument-list.ts
+++ b/lib/src/value/argument-list.ts
@@ -31,6 +31,8 @@ export class SassArgumentList extends SassList {
    */
   readonly keywordsInternal: OrderedMap<string, Value>;
 
+  private _keywordsAccessed = false;
+
   /**
    * Whether the `keywords` getter has been accessed.
    *
@@ -38,10 +40,12 @@ export class SassArgumentList extends SassList {
    * part of the package's public API and should not be accessed by user code.
    * It may be renamed or removed without warning in the future.
    */
-  keywordsAccessed = false;
+  get keywordsAccessed(): boolean {
+    return this._keywordsAccessed;
+  }
 
   get keywords(): OrderedMap<string, Value> {
-    this.keywordsAccessed = true;
+    this._keywordsAccessed = true;
     return this.keywordsInternal;
   }
 
diff --git a/lib/src/version.ts b/lib/src/version.ts
new file mode 100644
index 00000000..772b8258
--- /dev/null
+++ b/lib/src/version.ts
@@ -0,0 +1,24 @@
+// Copyright 2024 Google LLC. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import * as api from './vendor/sass';
+
+export class Version implements api.Version {
+  constructor(
+    readonly major: number,
+    readonly minor: number,
+    readonly patch: number
+  ) {}
+  static parse(version: string): Version {
+    const match = version.match(/^(\d+)\.(\d+)\.(\d+)$/);
+    if (match === null) {
+      throw new Error(`Invalid version ${version}`);
+    }
+    return new Version(
+      parseInt(match[1]),
+      parseInt(match[2]),
+      parseInt(match[3])
+    );
+  }
+}
diff --git a/npm/android-arm/package.json b/npm/android-arm/package.json
index 66248754..31001aef 100644
--- a/npm/android-arm/package.json
+++ b/npm/android-arm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-android-arm",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The android-arm binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/android-arm64/package.json b/npm/android-arm64/package.json
index 41f06166..849f79d7 100644
--- a/npm/android-arm64/package.json
+++ b/npm/android-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-android-arm64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The android-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/android-ia32/package.json b/npm/android-ia32/package.json
index 45453a15..beeeba0d 100644
--- a/npm/android-ia32/package.json
+++ b/npm/android-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-android-ia32",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The android-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/android-x64/package.json b/npm/android-x64/package.json
index a83a3bf1..825f950c 100644
--- a/npm/android-x64/package.json
+++ b/npm/android-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-android-x64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The android-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/darwin-arm64/package.json b/npm/darwin-arm64/package.json
index d91f90f1..fcfc9f1d 100644
--- a/npm/darwin-arm64/package.json
+++ b/npm/darwin-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-darwin-arm64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The darwin-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/darwin-x64/package.json b/npm/darwin-x64/package.json
index 6cd713c3..a3b9b1e3 100644
--- a/npm/darwin-x64/package.json
+++ b/npm/darwin-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-darwin-x64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The darwin-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-arm/package.json b/npm/linux-arm/package.json
index 57c3d1fb..45f56274 100644
--- a/npm/linux-arm/package.json
+++ b/npm/linux-arm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-arm",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-arm binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-arm64/package.json b/npm/linux-arm64/package.json
index bb3b2066..61d82dd5 100644
--- a/npm/linux-arm64/package.json
+++ b/npm/linux-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-arm64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-ia32/package.json b/npm/linux-ia32/package.json
index 632ff253..82a27457 100644
--- a/npm/linux-ia32/package.json
+++ b/npm/linux-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-ia32",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-musl-arm/package.json b/npm/linux-musl-arm/package.json
index ccdec118..0ed6b12c 100644
--- a/npm/linux-musl-arm/package.json
+++ b/npm/linux-musl-arm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-musl-arm",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-musl-arm binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-musl-arm64/package.json b/npm/linux-musl-arm64/package.json
index 0c9d14e3..c7192ad7 100644
--- a/npm/linux-musl-arm64/package.json
+++ b/npm/linux-musl-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-musl-arm64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-musl-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-musl-ia32/package.json b/npm/linux-musl-ia32/package.json
index 885bd534..a6726169 100644
--- a/npm/linux-musl-ia32/package.json
+++ b/npm/linux-musl-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-musl-ia32",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-musl-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-musl-x64/package.json b/npm/linux-musl-x64/package.json
index dca8e304..0d8d06d8 100644
--- a/npm/linux-musl-x64/package.json
+++ b/npm/linux-musl-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-musl-x64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-musl-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-x64/package.json b/npm/linux-x64/package.json
index f858a1d5..5db3156b 100644
--- a/npm/linux-x64/package.json
+++ b/npm/linux-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-x64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The linux-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-arm64/package.json b/npm/win32-arm64/package.json
index feb70cb9..9f6ee597 100644
--- a/npm/win32-arm64/package.json
+++ b/npm/win32-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-arm64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The win32-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-ia32/package.json b/npm/win32-ia32/package.json
index 6abde34e..40fa2ee2 100644
--- a/npm/win32-ia32/package.json
+++ b/npm/win32-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-ia32",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The win32-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-x64/package.json b/npm/win32-x64/package.json
index e986cd9e..21561855 100644
--- a/npm/win32-x64/package.json
+++ b/npm/win32-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-x64",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "description": "The win32-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/package.json b/package.json
index f4104d16..8295fa64 100644
--- a/package.json
+++ b/package.json
@@ -1,8 +1,8 @@
 {
   "name": "sass-embedded",
-  "version": "1.74.1",
+  "version": "1.77.3",
   "protocol-version": "3.0.0-dev",
-  "compiler-version": "1.74.1",
+  "compiler-version": "1.77.3",
   "description": "Node.js library that communicates with Embedded Dart Sass using the Embedded Sass protocol",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
@@ -35,23 +35,23 @@
     "test": "jest"
   },
   "optionalDependencies": {
-    "sass-embedded-android-arm": "1.74.1",
-    "sass-embedded-android-arm64": "1.74.1",
-    "sass-embedded-android-ia32": "1.74.1",
-    "sass-embedded-android-x64": "1.74.1",
-    "sass-embedded-darwin-arm64": "1.74.1",
-    "sass-embedded-darwin-x64": "1.74.1",
-    "sass-embedded-linux-arm": "1.74.1",
-    "sass-embedded-linux-arm64": "1.74.1",
-    "sass-embedded-linux-ia32": "1.74.1",
-    "sass-embedded-linux-x64": "1.74.1",
-    "sass-embedded-linux-musl-arm": "1.74.1",
-    "sass-embedded-linux-musl-arm64": "1.74.1",
-    "sass-embedded-linux-musl-ia32": "1.74.1",
-    "sass-embedded-linux-musl-x64": "1.74.1",
-    "sass-embedded-win32-arm64": "1.74.1",
-    "sass-embedded-win32-ia32": "1.74.1",
-    "sass-embedded-win32-x64": "1.74.1"
+    "sass-embedded-android-arm": "1.77.3",
+    "sass-embedded-android-arm64": "1.77.3",
+    "sass-embedded-android-ia32": "1.77.3",
+    "sass-embedded-android-x64": "1.77.3",
+    "sass-embedded-darwin-arm64": "1.77.3",
+    "sass-embedded-darwin-x64": "1.77.3",
+    "sass-embedded-linux-arm": "1.77.3",
+    "sass-embedded-linux-arm64": "1.77.3",
+    "sass-embedded-linux-ia32": "1.77.3",
+    "sass-embedded-linux-x64": "1.77.3",
+    "sass-embedded-linux-musl-arm": "1.77.3",
+    "sass-embedded-linux-musl-arm64": "1.77.3",
+    "sass-embedded-linux-musl-ia32": "1.77.3",
+    "sass-embedded-linux-musl-x64": "1.77.3",
+    "sass-embedded-win32-arm64": "1.77.3",
+    "sass-embedded-win32-ia32": "1.77.3",
+    "sass-embedded-win32-x64": "1.77.3"
   },
   "dependencies": {
     "@bufbuild/protobuf": "^1.0.0",
@@ -78,7 +78,7 @@
     "extract-zip": "^2.0.1",
     "gts": "^5.0.0",
     "jest": "^29.4.1",
-    "minipass": "7.0.4",
+    "minipass": "7.1.2",
     "npm-run-all": "^4.1.5",
     "shelljs": "^0.8.4",
     "simple-git": "^3.15.1",
diff --git a/tool/get-deprecations.ts b/tool/get-deprecations.ts
new file mode 100644
index 00000000..73618b4d
--- /dev/null
+++ b/tool/get-deprecations.ts
@@ -0,0 +1,67 @@
+// Generates the list of deprecations from spec/deprecations.yaml in the
+// language repo.
+
+import * as fs from 'fs';
+import {parse} from 'yaml';
+
+interface YamlData {
+  [key: string]: {
+    description: string;
+    'dart-sass': {
+      status: 'active' | 'future' | 'obsolete';
+      deprecated?: string;
+      obsolete?: string;
+    };
+  };
+}
+
+const yamlFile = 'build/sass/spec/deprecations.yaml';
+
+/**
+ * Converts a version string in the form X.Y.Z to be code calling the Version
+ * constructor, or null if the string is undefined.
+ */
+function toVersionCode(version: string | undefined): string {
+  if (!version) return 'null';
+  const match = version.match(/^(\d+)\.(\d+)\.(\d+)$/);
+  if (match === null) {
+    throw new Error(`Invalid version ${version}`);
+  }
+  return `new Version(${match[1]}, ${match[2]}, ${match[3]})`;
+}
+
+/**
+ * Generates the list of deprecations based on the YAML file in the language
+ * repo.
+ */
+export async function getDeprecations(outDirectory: string) {
+  const yamlText = fs.readFileSync(yamlFile, 'utf8');
+
+  const deprecations = parse(yamlText) as YamlData;
+  let tsText =
+    "import {Deprecations} from './sass';\n" +
+    "import {Version} from '../version';\n\n" +
+    'export const deprecations: Deprecations = {\n';
+  for (const [id, deprecation] of Object.entries(deprecations)) {
+    const key = id.includes('-') ? `'${id}'` : id;
+    const dartSass = deprecation['dart-sass'];
+    tsText +=
+      `  ${key}: {\n` +
+      `    id: '${id}',\n` +
+      `    description: '${deprecation.description}',\n` +
+      `    status: '${dartSass.status}',\n` +
+      `    deprecatedIn: ${toVersionCode(dartSass.deprecated)},\n` +
+      `    obsoleteIn: ${toVersionCode(dartSass.obsolete)},\n` +
+      '  },\n';
+  }
+  tsText +=
+    "  'user-authored': {\n" +
+    "    id: 'user-authored',\n" +
+    "    status: 'user',\n" +
+    '    deprecatedIn: null,\n' +
+    '    obsoleteIn: null,\n' +
+    '  },\n' +
+    '}\n';
+
+  fs.writeFileSync(`${outDirectory}/deprecations.ts`, tsText);
+}
diff --git a/tool/init.ts b/tool/init.ts
index a178675f..230cd09d 100644
--- a/tool/init.ts
+++ b/tool/init.ts
@@ -4,6 +4,7 @@
 
 import yargs from 'yargs';
 
+import {getDeprecations} from './get-deprecations';
 import {getEmbeddedCompiler} from './get-embedded-compiler';
 import {getLanguageRepo} from './get-language-repo';
 
@@ -65,6 +66,8 @@ void (async () => {
         await getEmbeddedCompiler(outPath);
       }
     }
+
+    await getDeprecations(outPath);
   } catch (error) {
     console.error(error);
     process.exitCode = 1;