diff --git a/tests/fixtures/functions/function_Dups.sql b/tests/fixtures/functions/function_Dups.sql
new file mode 100644
index 000000000..869003308
--- /dev/null
+++ b/tests/fixtures/functions/function_Dups.sql
@@ -0,0 +1,59 @@
+DROP FUNCTION IF EXISTS "MixedCase".function_dup(int, int, int);
+CREATE OR REPLACE FUNCTION "MixedCase".function_dup("Z" int, x int, y int)
+RETURNS TABLE("mVt" bytea, key text) AS $$
+  SELECT mvt, md5(mvt) as key FROM (
+    SELECT ST_AsMVT(tile, '"MixedCase".function_Dup', 4096, 'geom') as mvt FROM (
+      SELECT
+        ST_AsMVTGeom(
+            ST_Transform(ST_CurveToLine("Geom"), 3857),
+            ST_TileEnvelope("Z", x, y),
+            4096, 64, true) AS geom
+      FROM "MixedCase"."MixPoints"
+      WHERE "Geom" && ST_Transform(ST_TileEnvelope("Z", x, y), 4326)
+  ) as tile WHERE geom IS NOT NULL) src
+$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
+
+DROP FUNCTION IF EXISTS "MixedCase"."function_Dup"(int, int, int);
+CREATE OR REPLACE FUNCTION "MixedCase"."function_Dup"("Z" int, x int, y int)
+RETURNS TABLE("mVt" bytea, key text) AS $$
+  SELECT mvt, md5(mvt) as key FROM (
+    SELECT ST_AsMVT(tile, '"MixedCase".function_Dup', 4096, 'geom') as mvt FROM (
+      SELECT
+        ST_AsMVTGeom(
+            ST_Transform(ST_CurveToLine("Geom"), 3857),
+            ST_TileEnvelope("Z", x, y),
+            4096, 64, true) AS geom
+      FROM "MixedCase"."MixPoints"
+      WHERE "Geom" && ST_Transform(ST_TileEnvelope("Z", x, y), 4326)
+  ) as tile WHERE geom IS NOT NULL) src
+$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
+
+DROP FUNCTION IF EXISTS "MixedCase".function_dup(int, int, int, json);
+CREATE OR REPLACE FUNCTION "MixedCase".function_dup(z int, x int, y int, query json)
+RETURNS TABLE("mVt" bytea, key text) AS $$
+  SELECT mvt, md5(mvt) as key FROM (
+    SELECT ST_AsMVT(tile, '"MixedCase".function_Dup', 4096, 'geom') as mvt FROM (
+      SELECT
+        ST_AsMVTGeom(
+            ST_Transform(ST_CurveToLine("Geom"), 3857),
+            ST_TileEnvelope(z, x, y),
+            4096, 64, true) AS geom
+      FROM "MixedCase"."MixPoints"
+      WHERE "Geom" && ST_Transform(ST_TileEnvelope(z, x, y), 4326)
+  ) as tile WHERE geom IS NOT NULL) src
+$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
+
+DROP FUNCTION IF EXISTS "MixedCase".function_dup(int, int, int, jsonb);
+CREATE OR REPLACE FUNCTION "MixedCase".function_dup(z int, x int, y int, query jsonb)
+RETURNS TABLE("mVt" bytea, key text) AS $$
+  SELECT mvt, md5(mvt) as key FROM (
+    SELECT ST_AsMVT(tile, '"MixedCase".function_Dup', 4096, 'geom') as mvt FROM (
+      SELECT
+        ST_AsMVTGeom(
+            ST_Transform(ST_CurveToLine("Geom"), 3857),
+            ST_TileEnvelope(z, x, y),
+            4096, 64, true) AS geom
+      FROM "MixedCase"."MixPoints"
+      WHERE "Geom" && ST_Transform(ST_TileEnvelope(z, x, y), 4326)
+  ) as tile WHERE geom IS NOT NULL) src
+$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;