diff --git a/src/util.h b/src/util.h
index 7c54e490..cb61fe54 100644
--- a/src/util.h
+++ b/src/util.h
@@ -260,22 +260,13 @@ bool iends_with(InputIterator1 first1, InputIterator1 last1,
   return std::equal(first2, last2, last1 - (last2 - first2), CaseCmp());
 }
 
-inline bool iends_with(const std::string &a, const std::string &b) {
-  return iends_with(std::begin(a), std::end(a), std::begin(b), std::end(b));
+template <typename T, typename S> bool iends_with(const T &a, const S &b) {
+  return iends_with(a.begin(), a.end(), b.begin(), b.end());
 }
 
-inline bool iends_with(const StringRef &a, const StringRef &b) {
-  return iends_with(std::begin(a), std::end(a), std::begin(b), std::end(b));
-}
-
-template <typename CharT, size_t N>
-bool iends_with_l(const std::string &a, const CharT(&b)[N]) {
-  return iends_with(std::begin(a), std::end(a), b, b + N - 1);
-}
-
-template <typename CharT, size_t N>
-bool iends_with_l(const StringRef &a, const CharT(&b)[N]) {
-  return iends_with(std::begin(a), std::end(a), b, b + N - 1);
+template <typename T, typename CharT, size_t N>
+bool iends_with_l(const T &a, const CharT(&b)[N]) {
+  return iends_with(a.begin(), a.end(), b, b + N - 1);
 }
 
 template <typename InputIt1, typename InputIt2>
diff --git a/src/util_test.cc b/src/util_test.cc
index ae5a88bb..37604512 100644
--- a/src/util_test.cc
+++ b/src/util_test.cc
@@ -399,13 +399,16 @@ void test_util_ends_with(void) {
   CU_ASSERT(util::ends_with("ofoo", "foo"));
   CU_ASSERT(!util::ends_with("ofoo", "fo"));
 
-  CU_ASSERT(util::iends_with("fOo", "Foo"));
-  CU_ASSERT(util::iends_with("foo", ""));
-  CU_ASSERT(util::iends_with("oFoo", "fOO"));
-  CU_ASSERT(!util::iends_with("ofoo", "fo"));
+  CU_ASSERT(
+      util::iends_with(StringRef::from_lit("fOo"), StringRef::from_lit("Foo")));
+  CU_ASSERT(util::iends_with(StringRef::from_lit("foo"), StringRef{}));
+  CU_ASSERT(util::iends_with(StringRef::from_lit("oFoo"),
+                             StringRef::from_lit("fOO")));
+  CU_ASSERT(!util::iends_with(StringRef::from_lit("ofoo"),
+                              StringRef::from_lit("fo")));
 
-  CU_ASSERT(util::iends_with_l("oFoo", "fOO"));
-  CU_ASSERT(!util::iends_with_l("ofoo", "fo"));
+  CU_ASSERT(util::iends_with_l(StringRef::from_lit("oFoo"), "fOO"));
+  CU_ASSERT(!util::iends_with_l(StringRef::from_lit("ofoo"), "fo"));
 }
 
 void test_util_parse_http_date(void) {