diff --git a/nc_warnings.cmake b/nc_warnings.cmake
index e3d3444..18fe473 100644
--- a/nc_warnings.cmake
+++ b/nc_warnings.cmake
@@ -45,11 +45,9 @@ append_compile_flag(-Wshift-negative-value)
 append_compile_flag(-Wnull-dereference)
 append_compile_flag(-Wduplicated-cond)
 
-# useless-cast isn't usable on gcc-6.1 due to spurious warnings
+# useless-cast isn't usable on gcc-6.0 or gcc-6.1 due to spurious warnings
 # see gcc#70844
-#AS_IF([test "x$ax_cv_cxx_compiler_vendor" != "xgnu" || test "x$ax_cv_cxx_compiler_version" != "x6.1.0"], [
 append_compile_flag(-Wuseless-cast)
-#])
 
 # clang 3.7.1 warnings
 append_compile_flag(-Wshorten-64-to-32)