diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index a7a768e..545ccc5 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -1055,7 +1055,11 @@ CacheInvalidateHeapTuple(Relation relation,
 	Oid			databaseId;
 	Oid			relationId;
 
-	/* Do nothing during bootstrap */
+	/*
+     * Do nothing during bootstrap. It may seem silly to check this first since
+     * it will almost always be false, but it's not safe to assume that later
+     * checks can be done safely while in bootstrap.
+     */
 	if (IsBootstrapProcessingMode())
 		return;