diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index b14cd752ae..26a1f4cda9 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -184,8 +184,8 @@ void nvim_set_hl(uint64_t channel_id, Integer ns_id, String name, Dict(highlight
 
   // Setting URLs directly through highlight attributes is not supported
   if (HAS_KEY(val, highlight, url)) {
-    api_free_string(val->url);
-    val->url = NULL_STRING;
+    api_set_error(err, kErrorTypeValidation, "Invalid Key: 'url'");
+    return;
   }
 
   HlAttrs attrs = dict2hlattrs(val, true, &link_id, err);
diff --git a/test/functional/api/highlight_spec.lua b/test/functional/api/highlight_spec.lua
index 7078ce1dd9..9cd6b3125a 100644
--- a/test/functional/api/highlight_spec.lua
+++ b/test/functional/api/highlight_spec.lua
@@ -254,6 +254,10 @@ describe('API: set highlight', function()
     )
     assert_alive()
   end)
+  it("'url' is rejected with an error #38162", function()
+    eq("Invalid Key: 'url'", pcall_err(api.nvim_set_hl, 0, 'Test', { url = 'https://example.com' }))
+    assert_alive()
+  end)
 end)
 
 describe('API: get highlight', function()