diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 667df448732..43f289924e6 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -3464,6 +3464,15 @@ set_config_with_handle(const char *name, config_handle *handle,
 		return 0;
 	}
 
+	/*
+	 * Certain GUCs aren't safe to enable during bootstrap mode.  Silently
+	 * ignore attempts to set them to non-default values.
+	 */
+	if (unlikely(IsBootstrapProcessingMode()) &&
+		(record->flags & GUC_IGNORE_IN_BOOTSTRAP) &&
+		source != PGC_S_DEFAULT)
+		changeVal = false;
+
 	/*
 	 * Check if the option can be set at this time. See guc.h for the precise
 	 * rules.