diff --git a/library/platform_util.c b/library/platform_util.c
index 3d5cb5baa..1d34e768c 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -92,9 +92,11 @@ void mbedtls_platform_zeroize( void *buf, size_t len )
  * threading.h. However, this macro is not part of the Mbed TLS public API, so
  * we keep it private by only defining it in this file
  */
-#if ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) )
+#if ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) ) || \
+      ( defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR) )
 #define PLATFORM_UTIL_USE_GMTIME
-#endif /* ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) ) */
+#endif /* ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) ) || \
+             (defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR) ) */
 
 #endif /* !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
              ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
@@ -103,7 +105,7 @@ void mbedtls_platform_zeroize( void *buf, size_t len )
 struct tm *mbedtls_platform_gmtime_r( const mbedtls_time_t *tt,
                                       struct tm *tm_buf )
 {
-#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+#if defined(_WIN32) && !defined(PLATFORM_UTIL_USE_GMTIME)
     return( ( gmtime_s( tm_buf, tt ) == 0 ) ? tm_buf : NULL );
 #elif !defined(PLATFORM_UTIL_USE_GMTIME)
     return( gmtime_r( tt, tm_buf ) );
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 7481c5b4a..a620178f6 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -44,9 +44,12 @@ typedef UINT32 uint32_t;
 
 #include <string.h>
 
+#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__MINGW32__)
+#include <strings.h>
+#endif
+
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 #include <unistd.h>
-#include <strings.h>
 #endif
 
 /* Type for Hex parameters */