diff --git a/source/adapters/hip/kernel.cpp b/source/adapters/hip/kernel.cpp
index 8b0f49d780..60931cd014 100644
--- a/source/adapters/hip/kernel.cpp
+++ b/source/adapters/hip/kernel.cpp
@@ -171,11 +171,11 @@ urKernelGetNativeHandle(ur_kernel_handle_t, ur_native_handle_t *) {
 UR_APIEXPORT ur_result_t UR_APICALL urKernelSuggestMaxCooperativeGroupCountExp(
     ur_kernel_handle_t hKernel, size_t localWorkSize,
     size_t dynamicSharedMemorySize, uint32_t *pGroupCountRet) {
-  (void)hKernel;
-  (void)localWorkSize;
-  (void)dynamicSharedMemorySize;
-  *pGroupCountRet = 1;
-  return UR_RESULT_SUCCESS;
+  std::ignore = hKernel;
+  std::ignore = localWorkSize;
+  std::ignore = dynamicSharedMemorySize;
+  std::ignore = pGroupCountRet;
+  return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;
 }
 
 UR_APIEXPORT ur_result_t UR_APICALL urKernelSetArgValue(
diff --git a/source/adapters/opencl/kernel.cpp b/source/adapters/opencl/kernel.cpp
index f6fbdf9e3b..a93d09329e 100644
--- a/source/adapters/opencl/kernel.cpp
+++ b/source/adapters/opencl/kernel.cpp
@@ -360,13 +360,11 @@ UR_APIEXPORT ur_result_t UR_APICALL urKernelGetNativeHandle(
 }
 
 UR_APIEXPORT ur_result_t UR_APICALL urKernelSuggestMaxCooperativeGroupCountExp(
-    ur_kernel_handle_t hKernel, size_t localWorkSize,
-    size_t dynamicSharedMemorySize, uint32_t *pGroupCountRet) {
-  (void)hKernel;
-  (void)localWorkSize;
-  (void)dynamicSharedMemorySize;
-  *pGroupCountRet = 1;
-  return UR_RESULT_SUCCESS;
+    [[maybe_unused]] ur_kernel_handle_t hKernel,
+    [[maybe_unused]] size_t localWorkSize,
+    [[maybe_unused]] size_t dynamicSharedMemorySize,
+    [[maybe_unused]] uint32_t *pGroupCountRet) {
+  return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;
 }
 
 UR_APIEXPORT ur_result_t UR_APICALL urKernelCreateWithNativeHandle(