diff --git a/include/fmt/core.h b/include/fmt/core.h
index 4cfa00bfda38..1f782647ad80 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -94,7 +94,8 @@
 #  define FMT_CONSTEXPR_DECL
 #endif
 
-#if __cplusplus >= 202002L || \
+#if ((__cplusplus >= 202002L) && \
+     (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE > 9)) || \
     (__cplusplus >= 201709L && FMT_GCC_VERSION >= 1002)
 #  define FMT_CONSTEXPR20 constexpr
 #else