diff --git a/api/onnx_web/diffusers/run.py b/api/onnx_web/diffusers/run.py
index 8e32714f..bb90e0ab 100644
--- a/api/onnx_web/diffusers/run.py
+++ b/api/onnx_web/diffusers/run.py
@@ -497,7 +497,7 @@ def run_blend_pipeline(
     tile_size = get_base_tile(params, size)
 
     # resize mask to match source size
-    stage_source = sources[1]
+    stage_source = sources.pop()
     stage_mask = mask.resize(stage_source.size, Image.Resampling.BILINEAR)
 
     chain.stage(
diff --git a/api/scripts/test-release.py b/api/scripts/test-release.py
index 7372cbfd..9a9cdd4c 100644
--- a/api/scripts/test-release.py
+++ b/api/scripts/test-release.py
@@ -564,10 +564,15 @@ def run_test(
     passed = False
     for i in range(len(results)):
         result = results[i]
-        result.save(test_path(path.join("test-results", f"{test.name}-{i}.png")))
+        result_name = f"{test.name}-{i}.png"
+        result.save(test_path(path.join("test-results", result_name)))
 
-        ref_name = test_path(path.join("test-refs", f"{test.name}-{i}.png"))
-        ref = Image.open(ref_name) if path.exists(ref_name) else None
+        ref_name = test_path(path.join("test-refs", result_name))
+        if not path.exists(ref_name):
+            return TestResult.failed(test.name, f"no reference image for {result_name}")
+
+        ref = Image.open(ref_name)
+        logger.warning("comparing image %s to %s", result, ref)
 
         mse = find_mse(result, ref)
         threshold = test.mse_threshold * mse_mult