diff --git a/ryu/lib/ofctl_nicira_ext.py b/ryu/lib/ofctl_nicira_ext.py
index 98f5167a..aad8dcaa 100644
--- a/ryu/lib/ofctl_nicira_ext.py
+++ b/ryu/lib/ofctl_nicira_ext.py
@@ -39,9 +39,7 @@ def action_to_str(act, ofctl_action_to_str):
                                                       src_start, src_end)
 
     elif sub_type == nicira_ext.NXAST_REG_LOAD:
-        start = act.ofs
-        end = start + act.nbits
-        return 'NX_LOAD: {%s[%s..%s]: %x}' % (act.dst, start, end, act.value)
+        return 'NX_LOAD: {%s%s: %x}' % (act.dst, nicira_ext.ofs_nbits_str(act.ofs_nbits), act.value)
 
     elif sub_type == nicira_ext.NXAST_LEARN:
         specs = []
diff --git a/ryu/ofproto/nicira_ext.py b/ryu/ofproto/nicira_ext.py
index 19c8394c..9c2d2aaf 100644
--- a/ryu/ofproto/nicira_ext.py
+++ b/ryu/ofproto/nicira_ext.py
@@ -332,6 +332,17 @@ def ofs_nbits(start, end):
     return (start << 6) + (end - start)
 
 
+def ofs_nbits_str(n):
+    start = 0
+    while True:
+        start += 1
+        if (start << 6) > n:
+            break
+    start -= 1
+    end = n + start - (start << 6)
+    return "[%d..%d]" % (start, end)
+
+
 def nxm_header__(vendor, field, hasmask, length):
     return (vendor << 16) | (field << 9) | (hasmask << 8) | length