diff --git a/src/google/protobuf/port_def.inc b/src/google/protobuf/port_def.inc
index 1e360cc..e0283fe 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -609,7 +609,11 @@
 #define PROTOBUF_CONSTINIT [[clang::require_constant_initialization]]
 #define PROTOBUF_CONSTEXPR constexpr
 #elif PROTOBUF_GNUC_MIN(12, 0)
+#if PROTOBUF_CPLUSPLUS_MIN(201703L)
 #define PROTOBUF_CONSTINIT __constinit
+#else
+#define PROTOBUF_CONSTINIT
+#endif
 #define PROTOBUF_CONSTEXPR constexpr
 #else
 #define PROTOBUF_CONSTINIT