diff --git a/include/Support/Annotation.h b/include/Support/Annotation.h
index d0eca3d4dc4..f4b7c28202f 100644
--- a/include/Support/Annotation.h
+++ b/include/Support/Annotation.h
@@ -16,7 +16,7 @@
 #define SUPPORT_ANNOTATION_H
 
 #include <string>
-#include <assert.h>
+#include <cassert>
 
 class AnnotationID;
 class Annotation;
diff --git a/include/llvm/AbstractTypeUser.h b/include/llvm/AbstractTypeUser.h
index c1548c82f9b..5e163749682 100644
--- a/include/llvm/AbstractTypeUser.h
+++ b/include/llvm/AbstractTypeUser.h
@@ -21,15 +21,14 @@
 #ifndef LLVM_ABSTRACT_TYPE_USER_H
 #define LLVM_ABSTRACT_TYPE_USER_H
 
-//
-// This is the "master" include for assert.h
-// Whether this file needs it or not, it must always include assert.h for the
-// files which include llvm/AbstractTypeUser.h
+// This is the "master" include for <cassert> Whether this file needs it or not,
+// it must always include <cassert> for the files which include
+// llvm/AbstractTypeUser.h
 //
 // In this way, most every LLVM source file will have access to the assert()
-// macro without having to #include <assert.h> directly.
+// macro without having to #include <cassert> directly.
 //
-#include "Config/assert.h"
+#include <cassert>
 
 class Type;
 class DerivedType;
diff --git a/include/llvm/Analysis/DSSupport.h b/include/llvm/Analysis/DSSupport.h
index 7ba9b0c43ca..ae9d52a8692 100644
--- a/include/llvm/Analysis/DSSupport.h
+++ b/include/llvm/Analysis/DSSupport.h
@@ -10,7 +10,7 @@
 #include <vector>
 #include <functional>
 #include <string>
-#include <assert.h>
+#include <cassert>
 #include "Support/HashExtras.h"
 #include "Support/hash_set"
 
diff --git a/include/llvm/Analysis/DataStructure/DSSupport.h b/include/llvm/Analysis/DataStructure/DSSupport.h
index 7ba9b0c43ca..ae9d52a8692 100644
--- a/include/llvm/Analysis/DataStructure/DSSupport.h
+++ b/include/llvm/Analysis/DataStructure/DSSupport.h
@@ -10,7 +10,7 @@
 #include <vector>
 #include <functional>
 #include <string>
-#include <assert.h>
+#include <cassert>
 #include "Support/HashExtras.h"
 #include "Support/hash_set"
 
diff --git a/include/llvm/Support/Annotation.h b/include/llvm/Support/Annotation.h
index d0eca3d4dc4..f4b7c28202f 100644
--- a/include/llvm/Support/Annotation.h
+++ b/include/llvm/Support/Annotation.h
@@ -16,7 +16,7 @@
 #define SUPPORT_ANNOTATION_H
 
 #include <string>
-#include <assert.h>
+#include <cassert>
 
 class AnnotationID;
 class Annotation;