diff --git a/include/fmt/core.h b/include/fmt/core.h
index 4820219d..80113740 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -89,7 +89,8 @@
 # endif
 #endif
 
-#if FMT_HAS_FEATURE(cxx_explicit_conversions) || FMT_MSC_VER >= 1800
+#if FMT_HAS_FEATURE(cxx_explicit_conversions) || \
+  FMT_GCC_VERSION >= 405 || FMT_MSC_VER >= 1800
 # define FMT_EXPLICIT explicit
 #else
 # define FMT_EXPLICIT