diff --git a/.eslintrc.json b/.eslintrc.json
index e1bbe36..0003f18 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -19,6 +19,7 @@
         ],
         "@typescript-eslint/naming-convention": "warn",
         "@typescript-eslint/semi": "warn",
+        "@typescript-eslint/explicit-function-return-type": "warn",
         "curly": "warn",
         "eqeqeq": "warn",
         "no-throw-literal": "warn",
diff --git a/src/codeMarker.ts b/src/codeMarker.ts
index bb11aea..2fd267b 100644
--- a/src/codeMarker.ts
+++ b/src/codeMarker.ts
@@ -1025,7 +1025,7 @@ class WARoot {
      * @param auditRemote The audit remote to be configured.
      * @param gitSha The git SHA digest to be configured.
      */
-    updateGitConfig(clientRemote: string, auditRemote: string, gitSha: string) {
+    updateGitConfig(clientRemote: string, auditRemote: string, gitSha: string): void {
         this.clientRemote = clientRemote;
         this.gitRemote = auditRemote;
         this.gitSha = gitSha;
@@ -1059,7 +1059,7 @@ class MultiRootManager {
             this.roots.map((root) => ({ rootPath: root.rootPath, rootLabel: root.getRootLabel() }) as RootPathAndLabel),
         );
         // Add a listener for changes to the roots
-        const listener = async (event: vscode.WorkspaceFoldersChangeEvent) => {
+        const listener = async (event: vscode.WorkspaceFoldersChangeEvent): Promise<void> => {
             // Any removed or added roots will execute weAudit.toggleSavedFindings, which will cause a refresh
             // of the tree, and hence a recreation of the pathToEntryMap (which is important in case there is
             // only one workspace root left)
diff --git a/src/types.ts b/src/types.ts
index 5101a6e..37a9b73 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -203,7 +203,7 @@ export interface EntryDetails {
  * Creates a default entry details object.
  * @returns the default entry details object
  */
-export function createDefaultEntryDetails() {
+export function createDefaultEntryDetails(): EntryDetails {
     return {
         severity: FindingSeverity.Undefined,
         difficulty: FindingDifficulty.Undefined,
@@ -376,7 +376,7 @@ export function getEntryIndexFromArray(entry: Entry, array: Entry[]): number {
     return -1;
 }
 
-export function mergeTwoEntryArrays(a: Entry[], b: Entry[]) {
+export function mergeTwoEntryArrays(a: Entry[], b: Entry[]): Entry[] {
     // merge two arrays of entries
     // without duplicates
     const result: Entry[] = a;