diff --git a/wtformsparsleyjs/core.py b/wtformsparsleyjs/core.py
index 20ba6cc..be7ac41 100644
--- a/wtformsparsleyjs/core.py
+++ b/wtformsparsleyjs/core.py
@@ -76,12 +76,22 @@ def _ip_address_kwargs(kwargs):
         r'(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b$'
 
 
+def _range_kwargs(kwargs, vali, suffix=''):
+    if vali.min > 0 and vali.max > 0:
+        kwargs[u'data-range' + suffix] = u'[' + str(vali.min) + u',' + str(vali.max) + u']'
+    else:
+        if vali.min > 0:
+            kwargs[u'data-min' + suffix] = str(vali.min)
+        if vali.max > 0:
+            kwargs[u'data-max' + suffix] = str(vali.max)
+
+
 def _length_kwargs(kwargs, vali):
-    kwargs[u'data-rangelength'] = u'[' + str(vali.min) + u',' + str(vali.max) + u']'
+    _range_kwargs(kwargs, vali, suffix='length')
 
 
 def _number_range_kwargs(kwargs, vali):
-    kwargs[u'data-range'] = u'[' + str(vali.min) + u',' + str(vali.max) + u']'
+    _range_kwargs(kwargs, vali)
 
 
 def _required_kwargs(kwargs):