diff --git a/src/drr/colvar_UIestimator.h b/src/drr/colvar_UIestimator.h
index 3ca4a04accf93ff649f6b3ad5e27290c96c84ab4..bbc74a0b1269585634fd66de59336dc7d35801db 100644
--- a/src/drr/colvar_UIestimator.h
+++ b/src/drr/colvar_UIestimator.h
@@ -191,7 +191,7 @@ public:
     temp.resize(dimension);
   }
 
-  const T inline get_value(const std::vector<double> & x)
+  T inline get_value(const std::vector<double> & x)
   {
     return vector[convert_x(x)];
   }