diff --git a/include/Support/Annotation.h b/include/Support/Annotation.h
index 9642f03c804..d0eca3d4dc4 100644
--- a/include/Support/Annotation.h
+++ b/include/Support/Annotation.h
@@ -16,6 +16,7 @@
 #define SUPPORT_ANNOTATION_H
 
 #include <string>
+#include <assert.h>
 
 class AnnotationID;
 class Annotation;
diff --git a/include/llvm/Support/Annotation.h b/include/llvm/Support/Annotation.h
index 9642f03c804..d0eca3d4dc4 100644
--- a/include/llvm/Support/Annotation.h
+++ b/include/llvm/Support/Annotation.h
@@ -16,6 +16,7 @@
 #define SUPPORT_ANNOTATION_H
 
 #include <string>
+#include <assert.h>
 
 class AnnotationID;
 class Annotation;