diff --git a/simgear/props/PropertyInterpolationMgr.cxx b/simgear/props/PropertyInterpolationMgr.cxx
index ad8060e2..1e8ac02c 100644
--- a/simgear/props/PropertyInterpolationMgr.cxx
+++ b/simgear/props/PropertyInterpolationMgr.cxx
@@ -70,6 +70,12 @@ namespace simgear
           break;
         }
       }
+
+	  // needed to avoid incrementing an invalid iterator when we
+	  // erase the last interpolator
+	  if (it == _interpolators.end()) {
+		  break;
+	  }
     }
   }