diff --git a/dlib/matrix/matrix_expressions.h b/dlib/matrix/matrix_expressions.h
index fccf070bf..549a70057 100644
--- a/dlib/matrix/matrix_expressions.h
+++ b/dlib/matrix/matrix_expressions.h
@@ -1610,7 +1610,7 @@ namespace dlib
         T operator() (
             long,
             long c
-        ) const { return std::pow(10,start + c*inc);  }
+        ) const { return std::pow((T)10,start + c*inc);  }
 
         T operator() (
             long c