diff --git a/include/llvm/Support/DataTypes.h.in b/include/llvm/Support/DataTypes.h.in
index 81d4cff3e36..da87f8aa4c9 100644
--- a/include/llvm/Support/DataTypes.h.in
+++ b/include/llvm/Support/DataTypes.h.in
@@ -50,6 +50,8 @@
 #include <stdint.h>
 #endif
 
+#include <cmath>
+
 #ifdef _AIX
 #include "llvm/Support/AIXDataTypesFix.h"
 #endif