diff --git a/src/CallModel.hpp b/src/CallModel.hpp
index 5a1719c43ce2060eb32e96689b96cf5a0fb915e8..a611b239ba904ffeff6b8d4c55adf12d7ac586e7 100644
--- a/src/CallModel.hpp
+++ b/src/CallModel.hpp
@@ -63,7 +63,7 @@ public:
    SortableCallSource(Call* call=0) : count(0),callInfo(call) {}
    uint count;
    Call* callInfo;
-   const bool operator<(SortableCallSource other) {
+   bool operator<(SortableCallSource other) {
       return (other.count > count);
    }
 };