diff --git a/dlls/msvcp120/tests/msvcp120.c b/dlls/msvcp120/tests/msvcp120.c
index c1c7002f263..a35d1f60031 100644
--- a/dlls/msvcp120/tests/msvcp120.c
+++ b/dlls/msvcp120/tests/msvcp120.c
@@ -323,6 +323,10 @@ typedef struct
     void *tail;
 } critical_section;
 
+#define MTX_PLAIN 0x1
+#define MTX_TRY 0x2
+#define MTX_TIMED 0x4
+#define MTX_RECURSIVE 0x100
 typedef struct
 {
     DWORD flags;
@@ -335,6 +339,7 @@ static int (__cdecl *p__Mtx_init)(_Mtx_t*, int);
 static void (__cdecl *p__Mtx_destroy)(_Mtx_t*);
 static int (__cdecl *p__Mtx_lock)(_Mtx_t*);
 static int (__cdecl *p__Mtx_unlock)(_Mtx_t*);
+static int (__cdecl *p__Mtx_trylock)(_Mtx_t*);
 
 /* cnd */
 typedef void *_Cnd_t;
@@ -801,6 +806,8 @@ static BOOL init(void)
             "_Mtx_lock");
     SET(p__Mtx_unlock,
             "_Mtx_unlock");
+    SET(p__Mtx_trylock,
+            "_Mtx_trylock");
 
     SET(p__Cnd_init,
             "_Cnd_init");
@@ -2438,6 +2445,42 @@ static void test__Pad(void)
     CloseHandle(_Pad__Launch_returned);
 }
 
+static void test__Mtx(void)
+{
+#
+    static int flags[] =
+    {
+        0, MTX_PLAIN, MTX_TRY, MTX_TIMED, MTX_RECURSIVE,
+        MTX_PLAIN|MTX_TRY, MTX_PLAIN|MTX_RECURSIVE, MTX_PLAIN|0xbeef
+    };
+    _Mtx_t mtx;
+    int i, r, expect;
+
+    for (i=0; i<ARRAY_SIZE(flags); i++)
+    {
+        if (flags[i] == MTX_PLAIN || flags[i] & MTX_RECURSIVE)
+            expect = 0;
+        else
+            expect = 3;
+
+        r = p__Mtx_init(&mtx, flags[i]);
+        ok(!r, "failed to init mtx (flags %x)\n", flags[i]);
+
+        r = p__Mtx_trylock(&mtx);
+        ok(!r, "_Mtx_trylock returned %x (flags %x)\n", r, flags[i]);
+        r = p__Mtx_trylock(&mtx);
+        ok(r == expect, "_Mtx_trylock returned %x (flags %x)\n", r, flags[i]);
+        if(!r) p__Mtx_unlock(&mtx);
+
+        r = p__Mtx_lock(&mtx);
+        ok(r == expect, "_Mtx_lock returned %x (flags %x)\n", r, flags[i]);
+        if(!r) p__Mtx_unlock(&mtx);
+
+        p__Mtx_unlock(&mtx);
+        p__Mtx_destroy(&mtx);
+    }
+}
+
 static void test_threads__Mtx(void)
 {
     void *mtx = NULL;
@@ -3341,6 +3384,7 @@ START_TEST(msvcp120)
     test_thrd();
     test_cnd();
     test__Pad();
+    test__Mtx();
     test_threads__Mtx();
 
     test_vector_base_v4__Segment_index_of();
diff --git a/dlls/msvcp90/misc.c b/dlls/msvcp90/misc.c
index 0e81b8d1889..dac6a96564c 100644
--- a/dlls/msvcp90/misc.c
+++ b/dlls/msvcp90/misc.c
@@ -681,7 +681,10 @@ __ASM_GLOBAL_FUNC(call_thiscall_func,
 
 #endif /* __i386__ */
 
-#define MTX_MULTI_LOCK 0x100
+#define MTX_PLAIN 0x1
+#define MTX_TRY 0x2
+#define MTX_TIMED 0x4
+#define MTX_RECURSIVE 0x100
 #define MTX_LOCKED 3
 typedef struct
 {
@@ -703,7 +706,7 @@ typedef _Mtx_t *_Mtx_arg_t;
 
 void __cdecl _Mtx_init_in_situ(_Mtx_t mtx, int flags)
 {
-    if(flags & ~MTX_MULTI_LOCK)
+    if(flags & ~(MTX_PLAIN | MTX_TRY | MTX_TIMED | MTX_RECURSIVE))
         FIXME("unknown flags ignored: %x\n", flags);
 
     mtx->flags = flags;
@@ -740,7 +743,8 @@ int __cdecl _Mtx_lock(_Mtx_arg_t mtx)
     if(MTX_T_FROM_ARG(mtx)->thread_id != GetCurrentThreadId()) {
         call_func1(critical_section_lock, &MTX_T_FROM_ARG(mtx)->cs);
         MTX_T_FROM_ARG(mtx)->thread_id = GetCurrentThreadId();
-    }else if(!(MTX_T_FROM_ARG(mtx)->flags & MTX_MULTI_LOCK)) {
+    }else if(!(MTX_T_FROM_ARG(mtx)->flags & MTX_RECURSIVE)
+            && MTX_T_FROM_ARG(mtx)->flags != MTX_PLAIN) {
         return MTX_LOCKED;
     }
 
@@ -764,7 +768,8 @@ int __cdecl _Mtx_trylock(_Mtx_arg_t mtx)
         if(!call_func1(critical_section_trylock, &MTX_T_FROM_ARG(mtx)->cs))
             return MTX_LOCKED;
         MTX_T_FROM_ARG(mtx)->thread_id = GetCurrentThreadId();
-    }else if(!(MTX_T_FROM_ARG(mtx)->flags & MTX_MULTI_LOCK)) {
+    }else if(!(MTX_T_FROM_ARG(mtx)->flags & MTX_RECURSIVE)
+            && MTX_T_FROM_ARG(mtx)->flags != MTX_PLAIN) {
         return MTX_LOCKED;
     }