diff --git a/include/llvm/Support/SourceMgr.h b/include/llvm/Support/SourceMgr.h
index 176e852..bed2f13 100644
--- a/include/llvm/Support/SourceMgr.h
+++ b/include/llvm/Support/SourceMgr.h
@@ -139,7 +139,7 @@
     : Filename(FN), LineNo(Line), ColumnNo(Col), Message(Msg),
       LineContents(LineStr), ShowLine(showline) {}
 
-  void Print(const char *ProgName, raw_ostream &S);
+  void Print(const char *ProgName, raw_ostream &S) const;
 };
 
 }  // end llvm namespace
diff --git a/lib/Support/SourceMgr.cpp b/lib/Support/SourceMgr.cpp
index 7652e18..83c7964 100644
--- a/lib/Support/SourceMgr.cpp
+++ b/lib/Support/SourceMgr.cpp
@@ -188,7 +188,7 @@
 // SMDiagnostic Implementation
 //===----------------------------------------------------------------------===//
 
-void SMDiagnostic::Print(const char *ProgName, raw_ostream &S) {
+void SMDiagnostic::Print(const char *ProgName, raw_ostream &S) const {
   if (ProgName && ProgName[0])
     S << ProgName << ": ";