diff --git a/Eigen/src/Core/util/DisableStupidWarnings.h b/Eigen/src/Core/util/DisableStupidWarnings.h
index 76ae1c9bd..4501d3248 100755
--- a/Eigen/src/Core/util/DisableStupidWarnings.h
+++ b/Eigen/src/Core/util/DisableStupidWarnings.h
@@ -56,7 +56,7 @@
     #pragma GCC diagnostic push
   #endif
   // g++ warns about local variables shadowing member functions, which is too strict
-//  #pragma GCC diagnostic ignored "-Wshadow"
+  #pragma GCC diagnostic ignored "-Wshadow"
   #if __GNUC__ == 4 && __GNUC_MINOR__ < 8
     // Until g++-4.7 there are warnings when comparing unsigned int vs 0, even in templated functions:
     #pragma GCC diagnostic ignored "-Wtype-limits"