diff --git a/DESCRIPTION b/DESCRIPTION
index f30c31d..2019222 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -21,13 +21,14 @@ Language: en-US
 License: Apache License (>= 2)
 LazyData: true
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
-Depends: R (>= 3.5)
+RoxygenNote: 7.3.1
+Depends: R (>= 4.0)
 Imports:
-    jsonlite (>= 1.8.0),
+    yyjsonr (>= 0.1.18),
     jsonvalidate (>= 1.3.1)
 Suggests:
     testthat (>= 2.1.0),
+    jsonlite (>= 1.8.0),
     knitr,
     haven,
     rmarkdown,
diff --git a/NAMESPACE b/NAMESPACE
index c882af0..a9a5cd9 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -23,8 +23,12 @@ export(set_source_system)
 export(set_study_oid)
 export(validate_dataset_json)
 export(write_dataset_json)
-importFrom(jsonlite,fromJSON)
-importFrom(jsonlite,toJSON)
 importFrom(jsonvalidate,json_validate)
 importFrom(tools,file_path_sans_ext)
 importFrom(utils,tail)
+importFrom(yyjsonr,opts_read_json)
+importFrom(yyjsonr,opts_write_json)
+importFrom(yyjsonr,read_json_file)
+importFrom(yyjsonr,read_json_str)
+importFrom(yyjsonr,write_json_file)
+importFrom(yyjsonr,write_json_str)
diff --git a/R/dataset_metadata.R b/R/dataset_metadata.R
index 22edcb1..e65560e 100644
--- a/R/dataset_metadata.R
+++ b/R/dataset_metadata.R
@@ -95,7 +95,7 @@ set_item_data <- function(x, .data, ...) {
 
   # Insert into object in proper spots
   x[[1]][['records']] <- records
-  x[[1]][['itemData']] <- item_data
+  x[[1]][['itemData']] <- unname(item_data)
   x
 }
 
diff --git a/R/read_dataset_json.R b/R/read_dataset_json.R
index 161b382..a389558 100644
--- a/R/read_dataset_json.R
+++ b/R/read_dataset_json.R
@@ -23,19 +23,32 @@
 #' dat <- read_dataset_json(js)
 read_dataset_json <- function(file) {
 
+  json_opts <- yyjsonr::opts_read_json(
+    promote_num_to_string = TRUE
+  )
+
   if (path_is_url(file)) {
     # Url?
     file_contents <- read_from_url(file)
+    ds_json <- yyjsonr::read_json_str(
+      file_contents,
+      opts = json_opts
+    )
   } else if (file.exists(file)) {
     # File on disk?
-    file_contents <- readLines(file)
+    ds_json <- yyjsonr::read_json_file(
+      file,
+      opts = json_opts
+    )
   } else {
     # Direct file contents?
-    file_contents <- file
+    ds_json <- yyjsonr::read_json_str(
+      file,
+      opts = json_opts
+    )
   }
 
-  # Read the file and convert to datasetjson object
-  ds_json <- jsonlite::fromJSON(file_contents)
+
 
   # Pull the object out with a lot of assumptions because the format has already
   # been validated
diff --git a/R/write_dataset_json.R b/R/write_dataset_json.R
index af7c165..099bba0 100644
--- a/R/write_dataset_json.R
+++ b/R/write_dataset_json.R
@@ -32,18 +32,23 @@ write_dataset_json <- function(x, file, pretty=FALSE) {
   }
 
   # Create the JSON text
-  js <- jsonlite::toJSON(
-    x,
-    dataframe = "values",
-    na = "null",
+  json_opts <- yyjsonr::opts_write_json(
+    pretty = pretty,
     auto_unbox = TRUE,
-    pretty = pretty)
+  )
 
   if (!missing(file)) {
     # Write file to disk
-    cat(js, "\n", file = file)
+    yyjsonr::write_json_file(
+      x,
+      filename = file,
+      opts = json_opts
+    )
   } else {
     # Print to console
-    js
+    yyjsonr::write_json_str(
+      x,
+      opts = json_opts
+    )
   }
 }
diff --git a/R/zzz.R b/R/zzz.R
index bba701f..9e26d2b 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -1,5 +1,5 @@
 #' @importFrom jsonvalidate json_validate
-#' @importFrom jsonlite fromJSON toJSON
+#' @importFrom yyjsonr opts_write_json opts_read_json write_json_file write_json_str read_json_str read_json_file
 #' @importFrom tools file_path_sans_ext
 #' @importFrom utils tail
 NULL
diff --git a/man/read_dataset_json.Rd b/man/read_dataset_json.Rd
index b5ce954..811cc6f 100644
--- a/man/read_dataset_json.Rd
+++ b/man/read_dataset_json.Rd
@@ -21,6 +21,7 @@ either a file path on disk of a URL which contains the Dataset JSON file.
 # Read from disk
 \dontrun{
   dat <- read_dataset_json("path/to/file.json")
+ # Read file from URL
   dat <- dataset_json('https://www.somesite.com/file.json')
 }
 
diff --git a/tests/testthat/test-datasetjson.R b/tests/testthat/test-datasetjson.R
index 131ff46..52576a0 100644
--- a/tests/testthat/test-datasetjson.R
+++ b/tests/testthat/test-datasetjson.R
@@ -49,10 +49,10 @@ test_that("datasetjson object builds with minimal defaults", {
   expect_equal(ds_json$clinicalData$itemGroupData$IG.IRIS$items, iris_items_list)
 
   # Verify that data are attached properly with ITEMGRPUPSEQ attached
-  iris_test <- cbind(
+  iris_test <- unname(cbind(
     ITEMGROUPDATASEQ = 1:nrow(iris),
     iris
-  )
+  ))
 
   expect_equal(ds_json$clinicalData$itemGroupData$IG.IRIS$itemData, iris_test)
 })