--- a/contrib/btree_gist/sql/float4.sql
+++ b/contrib/btree_gist/sql/float4.sql
@@ -35,3 +35,11 @@ SELECT count(*) FROM float4tmp WHERE a >  -179.0::float4;
 EXPLAIN (COSTS OFF)
 SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
 SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
+
+INSERT INTO float4tmp VALUES ('NaN'), ('NaN');
+
+SET enable_seqscan=off;
+
+SELECT count(*) FROM float4tmp WHERE a = 'NaN';
+
+RESET enable_seqscan;
diff --git a/contrib/btree_gist/sql/float8.sql