diff --git a/cfg/std.cfg b/cfg/std.cfg
index 6266f35ca..c65f16c1d 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -2347,7 +2347,9 @@
     <returnValue type="size_t"/>
     <noreturn>false</noreturn>
     <leak-ignore/>
-    <arg nr="1" direction="out"/>
+    <arg nr="1" direction="out">
+      <not-uninit indirect="1"/>
+    </arg>
     <arg nr="2" direction="in">
       <not-null/>
       <not-uninit/>
diff --git a/test/cfg/std.c b/test/cfg/std.c
index 7e41ab410..f43a8acaf 100644
--- a/test/cfg/std.c
+++ b/test/cfg/std.c
@@ -1642,13 +1642,21 @@ void uninitvar_mbsinit(void)
     (void)mbsinit(ps);
 }
 
-void uninitvar_mbstowcs(void)
+void uninitvar_mbstowcs(wchar_t* d, const char* s, size_t m)
 {
-    wchar_t *ws;
-    char *s;
-    size_t n;
+    wchar_t *dest;
+    char *src;
+    size_t max;
+    
     // cppcheck-suppress uninitvar
-    (void)mbstowcs(ws,s,n);
+    (void)mbstowcs(dest,s,m);
+    // cppcheck-suppress uninitvar
+    (void)mbstowcs(d,src,m);
+    // cppcheck-suppress uninitvar
+    (void)mbstowcs(d,s,max);
+    
+    // No warning is expected
+    (void)mbstowcs(d,s,m);
 }
 
 void uninitvar_mbsrtowcs(wchar_t* d, const char** s, size_t m, mbstate_t *p)
@@ -1657,6 +1665,7 @@ void uninitvar_mbsrtowcs(wchar_t* d, const char** s, size_t m, mbstate_t *p)
     const char* src;
     size_t max;
     mbstate_t* ps;
+    
     // cppcheck-suppress uninitvar
     (void)mbsrtowcs(dest,s,m,p);
     // cppcheck-suppress uninitvar