diff --git a/src/outlines/types/__init__.py b/src/outlines/types/__init__.py
index a81143b2e..97e3e99bf 100644
--- a/src/outlines/types/__init__.py
+++ b/src/outlines/types/__init__.py
@@ -117,8 +117,8 @@ def __getattr__(self, name):
     r"[a-fA-F0-9]{12}"
 )
 ipv4 = Regex(
-    r"((25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})\.){3}"
-    r"(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})"
+    r"((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])\.){3}"
+    r"(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])"
 )
 
 # SemVer 2.0.0: https://semver.org/
diff --git a/tests/types/test_custom_types.py b/tests/types/test_custom_types.py
index ae2fa5aea..5fda51238 100644
--- a/tests/types/test_custom_types.py
+++ b/tests/types/test_custom_types.py
@@ -98,6 +98,10 @@
         (types.ipv4, "1.2.256.3", False),
         (types.ipv4, "1.2.3.256", False),
         (types.ipv4, "1.2.3", False),
+        (types.ipv4, "01.1.1.1", False),
+        (types.ipv4, "00.0.0.0", False),
+        (types.ipv4, "1.02.3.4", False),
+        (types.ipv4, "1.1.1.09", False),
         (types.ipv4, "1.2.3.4.5", False),
         (types.ipv4, "1.2.3.4.", False),
         (types.ipv4, ".1.2.3.4", False),