diff --git a/promql/promqltest/testdata/functions.test b/promql/promqltest/testdata/functions.test
index 7bba44869e..fb84f8bd24 100644
--- a/promql/promqltest/testdata/functions.test
+++ b/promql/promqltest/testdata/functions.test
@@ -234,11 +234,25 @@ clear
 load 5m
 	http_requests{path="/foo"}	0 50 100 150 200
 	http_requests{path="/bar"}	200 150 100 50 0
+	http_requests_gauge{path="/foo"} {{schema:0 sum:0 count:0 buckets:[0 0 0] counter_reset_hint:gauge}}+{{schema:0 sum:1 count:2 buckets:[1 1 1] counter_reset_hint:gauge}}x5
+	http_requests_counter{path="/foo"} {{schema:0 sum:0 count:0 buckets:[0 0 0]}}+{{schema:0 sum:1 count:2 buckets:[1 1 1]}}x5
+	http_requests_mix{path="/foo"} 0 50 100 {{schema:0 sum:0 count:0 buckets:[0 0 0] counter_reset_hint:gauge}} {{schema:0 sum:1 count:2 buckets:[1 1 1] counter_reset_hint:gauge}}
 
 eval instant at 20m delta(http_requests[20m])
 	{path="/foo"} 200
 	{path="/bar"} -200
 
+eval instant at 20m delta(http_requests_gauge[20m])
+	{path="/foo"} {{schema:0 sum:4 count:8 buckets:[4 4 4]}}
+
+# delta emits warn annotation for non-gauge histogram types.
+eval_warn instant at 20m delta(http_requests_counter[20m])
+	{path="/foo"} {{schema:0 sum:4 count:8 buckets:[4 4 4]}}
+
+# delta emits warn annotation for mix of histogram and floats.
+eval_warn instant at 20m delta(http_requests_mix[20m])
+	#empty
+
 clear
 
 # Tests for idelta().