Replace 'thread safe' by 'thread-safe' in the documentation
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 439a1cd..17d08b2 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -147,7 +147,7 @@
*
* \note mbedtls_platform_gmtime_r() is an abstraction in platform_util.h that
* behaves similarly to the gmtime() function from the C standard,
- * but is thread safe. Mbed TLS will try to identify the underlying platform
+ * but is thread-safe. Mbed TLS will try to identify the underlying platform
* and configure an appropriate underlying implementation (e.g. gmtime_r() for
* POSIX and gmtime_s() for Windows). If this is not possible, then
* gmtime() will be used. Refer to the documentation for
@@ -3101,7 +3101,7 @@
* mbedtls_platform_gmtime_r(). This replaces the default implementation in
* platform_util.c.
*
- * gmtime() is not a thread safe function as defined in the C standard. The
+ * gmtime() is not a thread-safe function as defined in the C standard. The
* library will try to use safer implementations of this function, such as
* gmtime_r() when available. However, if Mbed TLS cannot identify the target
* system, the implementation of mbedtls_platform_gmtime_r() will default to
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index 82b1fd0..66a8221 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -68,7 +68,7 @@
#if defined(MBEDTLS_HAVE_TIME_DATE)
/**
- * \brief Thread safe implementation of gmtime()
+ * \brief Thread-safe implementation of gmtime()
*
* The function is an abstraction that when called behaves similar
* to the gmtime() function from the C standard, but is thread