diff --git a/include/fmt/compile.h b/include/fmt/compile.h
index b2bf1ba10465..296ef42c697d 100644
--- a/include/fmt/compile.h
+++ b/include/fmt/compile.h
@@ -36,8 +36,7 @@ template <typename OutputIt> class truncating_iterator_base {
   using difference_type = std::ptrdiff_t;
   using pointer = void;
   using reference = void;
-  using _Unchecked_type =
-      truncating_iterator_base;  // Mark iterator as checked.
+  FMT_UNCHECKED_ITERATOR(truncating_iterator_base);
 
   OutputIt base() const { return out_; }
   size_t count() const { return count_; }
diff --git a/include/fmt/core.h b/include/fmt/core.h
index 1c81bbd2d980..44cfde3191cb 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -217,6 +217,13 @@
 #  endif
 #endif
 
+#ifdef _MSC_VER
+#  define FMT_UNCHECKED_ITERATOR(It) \
+    using _Unchecked_type = It  // Mark iterator as checked.
+#else
+#  define FMT_UNCHECKED_ITERATOR(It) using DummyTypeName = It
+#endif
+
 #ifndef FMT_BEGIN_NAMESPACE
 #  define FMT_BEGIN_NAMESPACE \
     namespace fmt {           \
@@ -1498,7 +1505,7 @@ class appender : public std::back_insert_iterator<detail::buffer<char>> {
  public:
   using std::back_insert_iterator<detail::buffer<char>>::back_insert_iterator;
   appender(base it) noexcept : base(it) {}
-  using _Unchecked_type = appender;  // Mark iterator as checked.
+  FMT_UNCHECKED_ITERATOR(appender);
 
   auto operator++() noexcept -> appender& { return *this; }
 
diff --git a/include/fmt/format.h b/include/fmt/format.h
index 6ed53aa96a4c..89e0079462f0 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1842,7 +1842,7 @@ class counting_iterator {
   using difference_type = std::ptrdiff_t;
   using pointer = void;
   using reference = void;
-  using _Unchecked_type = counting_iterator;  // Mark iterator as checked.
+  FMT_UNCHECKED_ITERATOR(counting_iterator);
 
   struct value_type {
     template <typename T> void operator=(const T&) {}
diff --git a/test/posix-mock-test.cc b/test/posix-mock-test.cc
index 8a2214e8b75b..32adbd5055d7 100644
--- a/test/posix-mock-test.cc
+++ b/test/posix-mock-test.cc
@@ -6,7 +6,7 @@
 // For the license information refer to format.h.
 
 // Disable bogus MSVC warnings.
-#ifndef _CRT_SECURE_NO_WARNINGS
+#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
 #  define _CRT_SECURE_NO_WARNINGS
 #endif
 
diff --git a/test/test-main.cc b/test/test-main.cc
index 268ed086815d..39d2789d33c3 100644
--- a/test/test-main.cc
+++ b/test/test-main.cc
@@ -15,9 +15,6 @@
 
 #ifdef _MSC_VER
 #  include <crtdbg.h>
-#else
-#  define _CrtSetReportFile(a, b)
-#  define _CrtSetReportMode(a, b)
 #endif
 
 int main(int argc, char** argv) {
@@ -28,11 +25,13 @@ int main(int argc, char** argv) {
   SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX |
                SEM_NOOPENFILEERRORBOX);
 #endif
+#ifdef _MSC_VER
   // Disable message boxes on assertion failures.
   _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
   _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
   _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
   _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
+#endif
   try {
     testing::InitGoogleTest(&argc, argv);
     testing::FLAGS_gtest_death_test_style = "threadsafe";