diff --git a/openmp/libomptarget/deviceRTLs/common/src/omptarget.cu b/openmp/libomptarget/deviceRTLs/common/src/omptarget.cu
--- a/openmp/libomptarget/deviceRTLs/common/src/omptarget.cu
+++ b/openmp/libomptarget/deviceRTLs/common/src/omptarget.cu
@@ -160,8 +160,12 @@
 }
 
 // Return true if the current target region is executed in SPMD mode.
+// NOTE: This function has to return 1 for SPMD mode, and 0 for generic mode.
+// That's because `__kmpc_parallel_51` checks if it's already in parallel region
+// by comparision between the parallel level and the return value of this
+// function.
 EXTERN int8_t __kmpc_is_spmd_exec_mode() {
-  return execution_param & OMP_TGT_EXEC_MODE_SPMD;
+  return (execution_param & OMP_TGT_EXEC_MODE_SPMD) == OMP_TGT_EXEC_MODE_SPMD;
 }
 
 EXTERN int8_t __kmpc_is_generic_main_thread(kmp_int32 Tid) {