diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 65ae682e298..c82bacd7c15 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -6554,6 +6554,13 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata,
 		if (index->hypothetical)
 			continue;
 
+		/*
+		 * get_actual_variable_endpoint uses the index-only-scan machinery, so
+		 * ignore indexes that can't use it on their first column.
+		 */
+		if (!index->canreturn[0])
+			continue;
+
 		/*
 		 * The first index column must match the desired variable, sortop, and
 		 * collation --- but we can use a descending-order index.