diff --git a/stuff/misc.hh b/stuff/misc.hh
index 446ca217700df3cd3eb78304068f7707d57b4c8c..7333340fa3d263d83ec825e30f69d121b7062a2d 100644
--- a/stuff/misc.hh
+++ b/stuff/misc.hh
@@ -150,7 +150,7 @@ struct RunInfo
 //! used in all runs to store L2 errors across runs
 typedef std::vector<RunInfo> RunInfoVector;
 
-typedef unsigned int RunInfoVectorMapKeyType;
+typedef int RunInfoVectorMapKeyType;
 
 typedef std::map<RunInfoVectorMapKeyType, RunInfoVector> RunInfoVectorMap;