diff --git a/hgext/extdiff.py b/hgext/extdiff.py
--- a/hgext/extdiff.py
+++ b/hgext/extdiff.py
@@ -254,7 +254,8 @@ def uisetup(ui):
         def save(cmd, path, diffopts):
             '''use closure to save diff command to use'''
             def mydiff(ui, repo, *pats, **opts):
-                return dodiff(ui, repo, path, diffopts, pats, opts)
+                return dodiff(ui, repo, path, diffopts + opts['option'],
+                              pats, opts)
             doc = _('''\
 use %(path)s to diff repository (or selected files)
 
diff --git a/tests/test-extdiff b/tests/test-extdiff
--- a/tests/test-extdiff
+++ b/tests/test-extdiff
@@ -65,3 +65,9 @@ chmod +x differ.py
 hg extdiff -p `pwd`/differ.py # will change to /tmp/extdiff.TMP and populate directories a.TMP and a and start tool
 echo '% diff in working directory, after'
 hg diff --git
+
+echo
+echo % test extdiff with --option
+hg extdiff -p echo -o this -c 1
+hg falabala -o this -c 1
+echo
diff --git a/tests/test-extdiff.out b/tests/test-extdiff.out
--- a/tests/test-extdiff.out
+++ b/tests/test-extdiff.out
@@ -68,3 +68,8 @@ new mode 100755
 -b
 +changed
 +edited
+
+% test extdiff with --option
+this a.8a5febb7f867/a a.34eed99112ab/a
+diffing this a.8a5febb7f867/a a.34eed99112ab/a
+