diff --git a/clang/lib/CodeGen/CGOpenMPRuntimeAMDGCN.cpp b/clang/lib/CodeGen/CGOpenMPRuntimeAMDGCN.cpp
index ccffdf43549fe1..33d4ab838af128 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeAMDGCN.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeAMDGCN.cpp
@@ -49,13 +49,12 @@ llvm::Value *CGOpenMPRuntimeAMDGCN::getGPUThreadID(CodeGenFunction &CGF) {
 llvm::Value *CGOpenMPRuntimeAMDGCN::getGPUNumThreads(CodeGenFunction &CGF) {
   CGBuilderTy &Bld = CGF.Builder;
   llvm::Module *M = &CGF.CGM.getModule();
-  const char *LocSize = "__ockl_get_local_size";
+  const char *LocSize = "__kmpc_amdgcn_gpu_num_threads";
   llvm::Function *F = M->getFunction(LocSize);
   if (!F) {
     F = llvm::Function::Create(
-        llvm::FunctionType::get(CGF.Int64Ty, {CGF.Int32Ty}, false),
+        llvm::FunctionType::get(CGF.Int32Ty, llvm::None, false),
         llvm::GlobalVariable::ExternalLinkage, LocSize, &CGF.CGM.getModule());
   }
-  return Bld.CreateTrunc(
-      Bld.CreateCall(F, {Bld.getInt32(0)}, "nvptx_num_threads"), CGF.Int32Ty);
+  return Bld.CreateCall(F, llvm::None, "nvptx_num_threads");
 }
diff --git a/clang/test/OpenMP/amdgcn_target_codegen.cpp b/clang/test/OpenMP/amdgcn_target_codegen.cpp
index 85ef69942a50d1..416ed06083b078 100644
--- a/clang/test/OpenMP/amdgcn_target_codegen.cpp
+++ b/clang/test/OpenMP/amdgcn_target_codegen.cpp
@@ -13,9 +13,8 @@ int test_amdgcn_target_tid_threads() {
 
   int arr[N];
 
-// CHECK: [[NUM_THREADS:%.+]] = call i64 @__ockl_get_local_size(i32 0)
-// CHECK-NEXT: [[VAR:%.+]] = trunc i64 [[NUM_THREADS]] to i32
-// CHECK-NEXT: sub nuw i32 [[VAR]], 64
+// CHECK: [[NUM_THREADS:%.+]] = call i32 @__kmpc_amdgcn_gpu_num_threads()
+// CHECK: sub nuw i32 [[NUM_THREADS]], 64
 // CHECK: call i32 @llvm.amdgcn.workitem.id.x()
 #pragma omp target
   for (int i = 0; i < N; i++) {
@@ -30,9 +29,8 @@ int test_amdgcn_target_tid_threads_simd() {
 
   int arr[N];
 
-// CHECK: [[NUM_THREADS:%.+]] = call i64 @__ockl_get_local_size(i32 0)
-// CHECK-NEXT: [[VAR:%.+]] = trunc i64 [[NUM_THREADS]] to i32
-// CHECK-NEXT: call void @__kmpc_spmd_kernel_init(i32 [[VAR]], i16 0)
+// CHECK: [[NUM_THREADS:%.+]] = call i32 @__kmpc_amdgcn_gpu_num_threads()
+// CHECK: call void @__kmpc_spmd_kernel_init(i32 [[NUM_THREADS]], i16 0)
 #pragma omp target simd
   for (int i = 0; i < N; i++) {
     arr[i] = 1;
diff --git a/openmp/libomptarget/deviceRTLs/amdgcn/src/amdgcn_interface.h b/openmp/libomptarget/deviceRTLs/amdgcn/src/amdgcn_interface.h
index f7c75c09362a24..80409d611f6f3e 100644
--- a/openmp/libomptarget/deviceRTLs/amdgcn/src/amdgcn_interface.h
+++ b/openmp/libomptarget/deviceRTLs/amdgcn/src/amdgcn_interface.h
@@ -15,4 +15,6 @@
 typedef uint64_t __kmpc_impl_lanemask_t;
 typedef uint32_t omp_lock_t; /* arbitrary type of the right length */
 
+EXTERN uint32_t __kmpc_amdgcn_gpu_num_threads();
+
 #endif
diff --git a/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip b/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip
index 9fbdc67b56ab61..3e70beb85d5b2e 100644
--- a/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip
+++ b/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip
@@ -144,6 +144,10 @@ DEVICE unsigned GetLaneId() {
   return __builtin_amdgcn_mbcnt_hi(~0u, __builtin_amdgcn_mbcnt_lo(~0u, 0u));
 }
 
+EXTERN uint32_t __kmpc_amdgcn_gpu_num_threads() {
+  return GetNumberOfThreadsInBlock();
+}
+
 // Stub implementations
-DEVICE void *__kmpc_impl_malloc(size_t ) { return nullptr }
+DEVICE void *__kmpc_impl_malloc(size_t) { return nullptr; }
 DEVICE void __kmpc_impl_free(void *) {}