diff --git a/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip b/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip
--- a/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip
+++ b/openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.hip
@@ -40,9 +40,13 @@
 
 DEVICE double __kmpc_impl_get_wtick() { return ((double)1E-9); }
 
-EXTERN uint64_t __clock64();
 DEVICE double __kmpc_impl_get_wtime() {
-  return ((double)1.0 / 745000000.0) * __clock64();
+#if __AMDGCN__ > 800
+  uint64_t t = __builtin_amdgcn_s_memrealtime();
+#else
+  uint64_t t = __builtin_amdgcn_s_memtime();
+#endif
+  return ((double)1.0 / 745000000.0) * t;
 }
 
 // Warp vote function