diff --git a/hypopg_index.c b/hypopg_index.c
index 3ad8187..6ce9b2a 100644
--- a/hypopg_index.c
+++ b/hypopg_index.c
@@ -101,8 +101,10 @@ static void hypo_estimate_index_simple(hypoIndex *entry,
 static void hypo_estimate_index(hypoIndex *entry, RelOptInfo *rel,
 					PlannerInfo *root);
 static int	hypo_estimate_index_colsize(hypoIndex *entry, int col);
+#if PG_VERSION_NUM >= 110000
 static void hypo_index_check_uniqueness_compatibility(IndexStmt *stmt,
 										  Oid relid, hypoIndex *entry);
+#endif
 static void hypo_index_pfree(hypoIndex *entry);
 static bool hypo_index_remove(Oid indexid);
 static const hypoIndex *hypo_index_store_parsetree(IndexStmt *node,
@@ -699,7 +701,6 @@ hypo_index_store_parsetree(IndexStmt *node, const char *queryString)
 		}
 
 #if PG_VERSION_NUM >= 110000
-
 		/*
 		 * check for uniqueness compatibility with (hypothetically)
 		 * partitioned tables