diff --git a/test/format-test.cc b/test/format-test.cc
index 31593833..4f6597a4 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -50,16 +50,6 @@
 #include "mock-allocator.h"
 #include "gtest-extra.h"
 
-#if defined(_WIN32) && !defined(__MINGW32__)
-// Fix MSVC warning about "unsafe" fopen.
-FILE *safe_fopen(const char *filename, const char *mode) {
-  FILE *f = 0;
-  errno = fopen_s(&f, filename, mode);
-  return f;
-}
-#define fopen safe_fopen
-#endif
-
 #undef min
 #undef max
 
@@ -1456,11 +1446,11 @@ TEST(FormatterTest, FormatExamples) {
   }
 
   const char *filename = "nonexistent";
-  FILE *ftest = fopen(filename, "r");
+  FILE *ftest = safe_fopen(filename, "r");
   int error_code = errno;
   EXPECT_TRUE(ftest == 0);
   EXPECT_SYSTEM_ERROR({
-    FILE *f = fopen(filename, "r");
+    FILE *f = safe_fopen(filename, "r");
     if (!f)
       throw fmt::SystemError(errno, "Cannot open file '{}'", filename);
   }, error_code, "Cannot open file 'nonexistent'");
diff --git a/test/gtest-extra-test.cc b/test/gtest-extra-test.cc
index 12c893c8..1d383cbc 100644
--- a/test/gtest-extra-test.cc
+++ b/test/gtest-extra-test.cc
@@ -40,19 +40,6 @@
 
 namespace {
 
-#ifdef _MSC_VER
-// Fix "secure" warning about using fopen without defining
-// _CRT_SECURE_NO_WARNINGS.
-FILE *safe_fopen(const char *filename, const char *mode) {
-  FILE *f = 0;
-  errno = fopen_s(&f, filename, mode);
-  return f;
-}
-#define fopen safe_fopen
-#else
-using std::fopen;
-#endif  // _MSC_VER
-
 // Tests that assertion macros evaluate their arguments exactly once.
 class SingleEvaluationTest : public ::testing::Test {
  protected:
diff --git a/test/posix-test.cc b/test/posix-test.cc
index 725c1507..4a9db7e3 100644
--- a/test/posix-test.cc
+++ b/test/posix-test.cc
@@ -184,7 +184,7 @@ TEST(FileTest, DefaultCtor) {
 }
 
 TEST(FileTest, OpenBufferedFileInCtor) {
-  FILE *fp = fopen("test-file", "w");
+  FILE *fp = safe_fopen("test-file", "w");
   std::fputs(FILE_CONTENT, fp);
   std::fclose(fp);
   File f("test-file", File::RDONLY);
diff --git a/test/util.h b/test/util.h
index 4027685c..a0d485eb 100644
--- a/test/util.h
+++ b/test/util.h
@@ -56,3 +56,14 @@ extern const char *const FILE_CONTENT;
 
 // Opens a buffered file for reading.
 fmt::BufferedFile open_buffered_file(FILE **fp = 0);
+
+inline FILE *safe_fopen(const char *filename, const char *mode) {
+#if defined(_WIN32) && !defined(__MINGW32__)
+  // Fix MSVC warning about "unsafe" fopen.
+  FILE *f = 0;
+  errno = fopen_s(&f, filename, mode);
+  return f;
+#else
+  return std::fopen(filename, mode);
+#endif
+}