diff --git a/folly/Portability.h b/folly/Portability.h
index 8334e2e99ab..e823f27f4d5 100644
--- a/folly/Portability.h
+++ b/folly/Portability.h
@@ -35,8 +35,12 @@
 static_assert(FOLLY_CPLUSPLUS >= 201703L, "__cplusplus >= 201703L");
 
 #if defined(__GNUC__) && !defined(__clang__)
+#if defined(FOLLY_CONFIG_TEMPORARY_DOWNGRADE_GCC)
+static_assert(__GNUC__ >= 9, "__GNUC__ >= 9");
+#else
 static_assert(__GNUC__ >= 10, "__GNUC__ >= 10");
 #endif
+#endif
 
 #if defined(_MSC_VER)
 static_assert(_MSC_VER >= 1920);