diff --git a/include/mbedtls/debug.h b/include/mbedtls/debug.h
index c1ad03275..74f5d5560 100644
--- a/include/mbedtls/debug.h
+++ b/include/mbedtls/debug.h
@@ -132,7 +132,7 @@
     /* (defined(__MINGW32__)  && __USE_MINGW_ANSI_STDIO == 0) || (defined(_MSC_VER) && _MSC_VER < 1800) */
 
 #if !defined(MBEDTLS_PRINTF_MS_TIME)
-#define MBEDTLS_PRINTF_MS_TIME MBEDTLS_PRINTF_LONGLONG
+#define MBEDTLS_PRINTF_MS_TIME PRId64
 #endif /* MBEDTLS_PRINTF_MS_TIME */
 
 #ifdef __cplusplus
diff --git a/include/mbedtls/platform_time.h b/include/mbedtls/platform_time.h
index 3158e2a83..c7973d9fc 100644
--- a/include/mbedtls/platform_time.h
+++ b/include/mbedtls/platform_time.h
@@ -43,6 +43,7 @@ typedef time_t mbedtls_time_t;
 typedef MBEDTLS_PLATFORM_MS_TIME_TYPE_MACRO mbedtls_ms_time_t;
 #else
 #include <stdint.h>
+#include <inttypes.h>
 typedef int64_t mbedtls_ms_time_t;
 #endif /* MBEDTLS_PLATFORM_MS_TIME_TYPE_MACRO */