diff --git a/libc/string/lib_strncpy.c b/libc/string/lib_strncpy.c
index a6bbf7ad1c..bd9de57a1d 100644
--- a/libc/string/lib_strncpy.c
+++ b/libc/string/lib_strncpy.c
@@ -55,7 +55,8 @@ char *strncpy(FAR char *dest, FAR const char *src, size_t n)
   char *ret = dest;     /* Value to be returned */
   char *end = dest + n; /* End of dest buffer + 1 byte */
 
-  while (dest != end && (*dest++ = *src++) != '\0');
+  while ((*dest++ = *src++) != '\0' && dest != end);
+  while (dest != end) *dest++ = '\0';
   return ret;
 }
 #endif