diff --git a/sanic/router.py b/sanic/router.py
index dcf3aeb5..4c1ea0a0 100644
--- a/sanic/router.py
+++ b/sanic/router.py
@@ -18,7 +18,7 @@ Parameter = namedtuple("Parameter", ["name", "cast"])
 REGEX_TYPES = {
     "string": (str, r"[^/]+"),
     "int": (int, r"-?\d+"),
-    "number": (float, r"-?[0-9\\.]+"),
+    "number": (float, r"-?(?:\d+(?:\.\d*)?|\.\d+)"),
     "alpha": (str, r"[A-Za-z]+"),
     "path": (str, r"[^/].*?"),
     "uuid": (
diff --git a/tests/test_routes.py b/tests/test_routes.py
index f3152935..3ccef135 100644
--- a/tests/test_routes.py
+++ b/tests/test_routes.py
@@ -365,9 +365,18 @@ def test_dynamic_route_number(app):
     request, response = app.test_client.get("/weight/1234.56")
     assert response.status == 200
 
+    request, response = app.test_client.get("/weight/.12")
+    assert response.status == 200
+
+    request, response = app.test_client.get("/weight/12.")
+    assert response.status == 200
+
     request, response = app.test_client.get("/weight/1234-56")
     assert response.status == 404
 
+    request, response = app.test_client.get("/weight/12.34.56")
+    assert response.status == 404
+
 
 def test_dynamic_route_regex(app):
     @app.route("/folder/<folder_id:[A-Za-z0-9]{0,4}>")
@@ -672,9 +681,18 @@ def test_dynamic_add_route_number(app):
     request, response = app.test_client.get("/weight/1234.56")
     assert response.status == 200
 
+    request, response = app.test_client.get("/weight/.12")
+    assert response.status == 200
+
+    request, response = app.test_client.get("/weight/12.")
+    assert response.status == 200
+
     request, response = app.test_client.get("/weight/1234-56")
     assert response.status == 404
 
+    request, response = app.test_client.get("/weight/12.34.56")
+    assert response.status == 404
+
 
 def test_dynamic_add_route_regex(app):
     async def handler(request, folder_id):