diff --git a/llvm/include/llvm-c/DataTypes.h b/llvm/include/llvm-c/DataTypes.h
--- a/llvm/include/llvm-c/DataTypes.h
+++ b/llvm/include/llvm-c/DataTypes.h
@@ -50,9 +50,11 @@
 
 #else /* _MSC_VER */
 #ifdef __cplusplus
+#include <cmath>
 #include <cstddef>
 #include <cstdlib>
 #else
+#include <math.h>
 #include <stddef.h>
 #include <stdlib.h>
 #endif