diff --git a/dlls/msvcrt/file.c b/dlls/msvcrt/file.c
index 385771e7bc3..f1af1b7abda 100644
--- a/dlls/msvcrt/file.c
+++ b/dlls/msvcrt/file.c
@@ -3683,6 +3683,7 @@ char * CDECL MSVCRT_tmpnam(char *s)
   {
     size = msvcrt_int_to_base32(tmpnam_unique++, tmpstr);
     memcpy(p, tmpstr, size);
+    p[size] = '\0';
     if (GetFileAttributesA(s) == INVALID_FILE_ATTRIBUTES &&
         GetLastError() == ERROR_FILE_NOT_FOUND)
       break;
@@ -3714,6 +3715,7 @@ MSVCRT_wchar_t * CDECL MSVCRT_wtmpnam(MSVCRT_wchar_t *s)
     {
         size = msvcrt_int_to_base32_w(tmpnam_unique++, tmpstr);
         memcpy(p, tmpstr, size*sizeof(MSVCRT_wchar_t));
+        p[size] = '\0';
         if (GetFileAttributesW(s) == INVALID_FILE_ATTRIBUTES &&
                 GetLastError() == ERROR_FILE_NOT_FOUND)
             break;
diff --git a/dlls/msvcrt/main.c b/dlls/msvcrt/main.c
index 5d6e37a554d..45191cd8d8a 100644
--- a/dlls/msvcrt/main.c
+++ b/dlls/msvcrt/main.c
@@ -74,6 +74,8 @@ static inline void msvcrt_free_tls_mem(void)
     HeapFree(GetProcessHeap(),0,tls->strerror_buffer);
     HeapFree(GetProcessHeap(),0,tls->wcserror_buffer);
     HeapFree(GetProcessHeap(),0,tls->time_buffer);
+    HeapFree(GetProcessHeap(),0,tls->tmpnam_buffer);
+    HeapFree(GetProcessHeap(),0,tls->wtmpnam_buffer);
     if(tls->have_locale) {
         free_locinfo(tls->locinfo);
         free_mbcinfo(tls->mbcinfo);