@@ -907,7 +907,11 @@ class Zstd extends ZlibBase {
       if (isAnyArrayBuffer(dictionary)) {
         dictionary = new Uint8Array(dictionary);
       } else {
-        dictionary = undefined;
+        throw new ERR_INVALID_ARG_TYPE(
+          'options.dictionary',
+          ['Buffer', 'TypedArray', 'DataView', 'ArrayBuffer'],
+          dictionary,
+        );
       }
     }
 
 
@@ -40,3 +40,24 @@ for (const dict of [arrayBuffer, uint8, dataView]) {
   const decompressed = zlib.zstdDecompressSync(compressed, { dictionary: dict });
   assert.strictEqual(decompressed.toString(), input.toString());
 }
+
+for (const dictionary of [null, 'string', 123, true, {}, [1, 2, 3]]) {
+  const options = { dictionary };
+  const expected = {
+    code: 'ERR_INVALID_ARG_TYPE',
+    name: 'TypeError',
+  };
+
+  assert.throws(() => zlib.createZstdCompress(options), expected);
+  assert.throws(() => zlib.createZstdDecompress(options), expected);
+  assert.throws(() => zlib.zstdCompressSync(input, options), expected);
+  assert.throws(() => zlib.zstdDecompressSync(input, options), expected);
+  assert.throws(
+    () => zlib.zstdCompress(input, options, common.mustNotCall()),
+    expected,
+  );
+  assert.throws(
+    () => zlib.zstdDecompress(input, options, common.mustNotCall()),
+    expected,
+  );
+}
Original file line number	Diff line number	Diff line change
`@@ -907,7 +907,11 @@ class Zstd extends ZlibBase {`
`907`	`907`	`if (isAnyArrayBuffer(dictionary)) {`
`908`	`908`	`dictionary = new Uint8Array(dictionary);`
`909`	`909`	`} else {`
`910`		`- dictionary = undefined;`
	`910`	`+ throw new ERR_INVALID_ARG_TYPE(`
	`911`	`+ 'options.dictionary',`
	`912`	`+ ['Buffer', 'TypedArray', 'DataView', 'ArrayBuffer'],`
	`913`	`+ dictionary,`
	`914`	`+ );`
`911`	`915`	`}`
`912`	`916`	`}`
`913`	`917`