diff --git a/property_tests/arbitraries/http/headers_arb.ts b/property_tests/arbitraries/http/headers_arb.ts
index 2717a661a5..413f7c54f5 100644
--- a/property_tests/arbitraries/http/headers_arb.ts
+++ b/property_tests/arbitraries/http/headers_arb.ts
@@ -15,5 +15,7 @@ export function HttpHeadersArb() {
 
     const HeaderArb = fc.tuple(HeaderNameArb, HeaderValueArb);
 
-    return fc.uniqueArray(HeaderArb, { selector: ([name, _]) => name });
+    return fc.uniqueArray(HeaderArb, {
+        selector: ([name, _]) => name.toLowerCase()
+    });
 }