diff --git a/pkg/utils/headers_test.go b/pkg/utils/headers_test.go
new file mode 100644
index 00000000000..ef7355699d6
--- /dev/null
+++ b/pkg/utils/headers_test.go
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2020 The Knative Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package utils
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestPassThroughHeaders(t *testing.T) {
+
+	testCases := map[string]struct {
+		additionalHeaders            http.Header
+		expectedPassedThroughHeaders int
+	}{
+		"pass through of two values": {
+			additionalHeaders: map[string][]string{
+				"not":                       {"passed", "through"},
+				"nor":                       {"this-one"},
+				"x-requEst-id":              {"1234"},
+				"knatIve-will-pass-through": {"true", "always"},
+			},
+			expectedPassedThroughHeaders: 2,
+		},
+		"nothing passes through": {
+			additionalHeaders: map[string][]string{
+				"not": {"passed", "through"},
+				"nor": {"this-one"},
+			},
+			expectedPassedThroughHeaders: 0,
+		},
+	}
+	for n, tc := range testCases {
+		t.Run(n, func(t *testing.T) {
+
+			headers := PassThroughHeaders(tc.additionalHeaders)
+			if len(headers) != tc.expectedPassedThroughHeaders {
+				t.Errorf("Not matching the expected number of passed through headers")
+			}
+		})
+	}
+}