diff --git a/src/isinetaddr.c b/src/isinetaddr.c
index 05a75fd..a157172 100644
--- a/src/isinetaddr.c
+++ b/src/isinetaddr.c
@@ -20,6 +20,7 @@ isinetaddr(const char *str)
   char buf[4];
   int i = 0, j = 0, k = 0;
   size_t len = (str == NULL ? 0 : strnlen(str, 16));
+
   for (size_t l = 0; l < len; l++) {
     if (str[l] == '.') {
       if (inrange(buf)) {
@@ -42,6 +43,11 @@ isinetaddr(const char *str)
       return 0;
     }
   }
-  return j == 3 && i <= 12 && inrange(buf);
+  if (k == 3 && j == 3) {
+    if (!inrange(buf)) {
+      return 0;
+    }
+  }
+  return j == 3 && i <= 12;
 }