diff --git a/test/base-test.cc b/test/base-test.cc
index 92415cbd..837c4e5e 100644
--- a/test/base-test.cc
+++ b/test/base-test.cc
@@ -874,22 +874,16 @@ struct custom_container {
   auto operator[](size_t) -> char& { return data; }
 };
 
-struct phantom_subscript_operator_container {
-  std::vector<char> buffer;
-
+struct phantom_subscript_container {
   using value_type = char;
 
-  auto size() const noexcept -> size_t { return buffer.size(); }
+  auto data() -> char*;
+  auto size() const -> size_t;
+  operator const char*() const;
+};
 
-  auto data() noexcept -> char* { return buffer.data(); }
-
-  auto data() const noexcept -> const char* { return buffer.data(); }
-
-  void resize(size_t n) { buffer.resize(n); }
-
-  void push_back(const char& value) { buffer.push_back(value); }
-
-  operator const char*() const noexcept { return data(); }
+struct real_subscript_container : phantom_subscript_container {
+  auto operator[](size_t) -> char&;
 };
 
 FMT_BEGIN_NAMESPACE
@@ -902,7 +896,8 @@ TEST(base_test, is_contiguous) {
   EXPECT_TRUE((fmt::is_contiguous<fmt::string_view>::value));
   EXPECT_TRUE((fmt::is_contiguous<std::vector<char>>::value));
   EXPECT_FALSE((fmt::is_contiguous<std::list<char>>::value));
-  EXPECT_FALSE((fmt::is_contiguous<phantom_subscript_operator_container>::value));
+  EXPECT_FALSE((fmt::is_contiguous<phantom_subscript_container>::value));
+  EXPECT_TRUE((fmt::is_contiguous<real_subscript_container>::value));
 }
 
 TEST(base_test, format_to_custom_container) {