diff --git a/include/clang/AST/CharUnits.h b/include/clang/AST/CharUnits.h
index cf909e8..5bfa19d 100644
--- a/include/clang/AST/CharUnits.h
+++ b/include/clang/AST/CharUnits.h
@@ -70,10 +70,24 @@
         Quantity += Other.Quantity;
         return *this;
       }
+      CharUnits& operator++ () {
+        ++Quantity;
+        return *this;
+      }
+      CharUnits operator++ (int) {
+        return CharUnits(Quantity++);
+      }
       CharUnits& operator-= (const CharUnits &Other) {
         Quantity -= Other.Quantity;
         return *this;
       }
+      CharUnits& operator-- () {
+        --Quantity;
+        return *this;
+      }
+      CharUnits operator-- (int) {
+        return CharUnits(Quantity--);
+      }
        
       // Comparison operators.
       bool operator== (const CharUnits &Other) const {