diff --git a/openmp/runtime/src/kmp_barrier.h b/openmp/runtime/src/kmp_barrier.h
--- a/openmp/runtime/src/kmp_barrier.h
+++ b/openmp/runtime/src/kmp_barrier.h
@@ -14,6 +14,7 @@
 #define KMP_BARRIER_H
 
 #include "kmp.h"
+#include "mm_malloc.h"
 
 // Use four cache lines: MLC tends to prefetch the next or previous cache line
 // creating a possible fake conflict between cores, so this is the only way to
diff --git a/openmp/runtime/src/kmp_os.h b/openmp/runtime/src/kmp_os.h
--- a/openmp/runtime/src/kmp_os.h
+++ b/openmp/runtime/src/kmp_os.h
@@ -1038,6 +1038,8 @@
     KMP_MFENCE_();                                                             \
   }
 #define KMP_SFENCE() KMP_SFENCE_()
+#else
+#define KMP_MFENCE()
 #endif
 
 #ifndef KMP_IMB