diff --git a/src/c11/impl/threads_posix.c b/src/c11/impl/threads_posix.c
index 736fc587be2..f8ebbab5cec 100644
--- a/src/c11/impl/threads_posix.c
+++ b/src/c11/impl/threads_posix.c
@@ -177,10 +177,9 @@ mtx_init(mtx_t *mtx, int type)
 {
     pthread_mutexattr_t attr;
     assert(mtx != NULL);
-    if (type != mtx_plain && type != mtx_timed && type != mtx_try
+    if (type != mtx_plain && type != mtx_timed
       && type != (mtx_plain|mtx_recursive)
-      && type != (mtx_timed|mtx_recursive)
-      && type != (mtx_try|mtx_recursive))
+      && type != (mtx_timed|mtx_recursive))
         return thrd_error;
 
     if ((type & mtx_recursive) == 0) {
diff --git a/src/c11/impl/threads_win32.c b/src/c11/impl/threads_win32.c
index 67aa29e48ac..af2add0839f 100644
--- a/src/c11/impl/threads_win32.c
+++ b/src/c11/impl/threads_win32.c
@@ -266,10 +266,9 @@ int
 mtx_init(mtx_t *mtx, int type)
 {
     assert(mtx != NULL);
-    if (type != mtx_plain && type != mtx_timed && type != mtx_try
+    if (type != mtx_plain && type != mtx_timed
       && type != (mtx_plain|mtx_recursive)
-      && type != (mtx_timed|mtx_recursive)
-      && type != (mtx_try|mtx_recursive))
+      && type != (mtx_timed|mtx_recursive))
         return thrd_error;
     InitializeCriticalSection((PCRITICAL_SECTION)mtx);
     return thrd_success;
diff --git a/src/c11/threads.h b/src/c11/threads.h
index ac6902f3b02..c091d22b5bc 100644
--- a/src/c11/threads.h
+++ b/src/c11/threads.h
@@ -133,9 +133,8 @@ typedef pthread_once_t  once_flag;
 enum
 {
    mtx_plain = 0,
-   mtx_try = 1,
+   mtx_recursive = 1,
    mtx_timed = 2,
-   mtx_recursive = 4
 };
 
 enum