@@ -134,6 +134,15 @@ function setDestTimestamps(src, dest) {
 // TODO(@anonrig): Move this function to C++.
 function onDir(srcStat, destStat, src, dest, opts) {
   if (!destStat) return copyDir(src, dest, opts, true, srcStat.mode);
+  if (opts.errorOnExist && !opts.force) {
+    throw new ERR_FS_CP_EEXIST({
+      message: `${dest} already exists`,
+      path: dest,
+      syscall: 'cp',
+      errno: EEXIST,
+      code: 'EEXIST',
+    });
+  }
   return copyDir(src, dest, opts);
 }
 
 
@@ -0,0 +1,32 @@
+// This tests that cpSync() throws if errorOnExist is true, force is false,
+// and the destination directory already exists (even if contents don't
+// conflict), matching the asynchronous cp() behavior.
+
+import '../common/index.mjs';
+import { nextdir } from '../common/fs.js';
+import assert from 'node:assert';
+import { cpSync, mkdirSync, writeFileSync } from 'node:fs';
+import tmpdir from '../common/tmpdir.js';
+
+tmpdir.refresh();
+
+const src = nextdir();
+const dest = nextdir();
+
+// Create source directory with a file
+mkdirSync(src);
+writeFileSync(`${src}/file.txt`, 'test');
+
+// Create destination directory with a different (non-conflicting) file
+mkdirSync(dest);
+writeFileSync(`${dest}/other.txt`, 'existing');
+
+// Should throw because dest directory already exists
+assert.throws(
+  () => cpSync(src, dest, {
+    recursive: true,
+    errorOnExist: true,
+    force: false,
+  }),
+  { code: 'ERR_FS_CP_EEXIST' },
+);