diff --git a/src/analysis/Histogram.cpp b/src/analysis/Histogram.cpp
index 87668290bf1f3530dc61d643ee2d2fbe213653cf..826c459d32403765cb886632c5663e98ac279ed5 100644
--- a/src/analysis/Histogram.cpp
+++ b/src/analysis/Histogram.cpp
@@ -212,6 +212,7 @@ public:
   void prepareForAveraging();
   void performOperations( const bool& from_update );
   void finishAveraging();
+  bool threadSafe() const { return !in_apply; }
   bool isPeriodic() { return false; }
   unsigned getNumberOfDerivatives();
   void turnOnDerivatives();