diff --git a/library/threading.c b/library/threading.c
index 9268da1..2bb932d 100644
--- a/library/threading.c
+++ b/library/threading.c
@@ -42,7 +42,7 @@
 
 #if !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
        ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
-         _POSIX_THREAD_SAFE_FUNCTIONS >= 20112L ) )
+         _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) )
 /*
  * This is a convenience shorthand macro to avoid checking the long
  * preprocessor conditions above. Ideally, we could expose this macro in
@@ -57,7 +57,7 @@
 
 #endif /* !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
              ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
-                _POSIX_THREAD_SAFE_FUNCTIONS >= 20112L ) ) */
+                _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) ) */
 
 #endif /* MBEDTLS_HAVE_TIME_DATE && !MBEDTLS_PLATFORM_GMTIME_R_ALT */