diff --git a/method/svn.py b/method/svn.py
index bb3b28f..50db3db 100644
--- a/method/svn.py
+++ b/method/svn.py
@@ -189,7 +189,7 @@ class SvnDiff3(Method):
         if path.startswith(cwd):
             path = path[len(cwd):]
 
-        cmd = "svn diff -r %s -r %s %r" % (rev1, rev2, path)
+        cmd = "svn diff -r %s:%s %r" % (rev1, rev2, path)
         (status, data) = commands.getstatusoutput(cmd)
         status = status >> 8