diff --git a/autoload/easy_align.vim b/autoload/easy_align.vim
index 1405d04..afd3a9f 100644
--- a/autoload/easy_align.vim
+++ b/autoload/easy_align.vim
@@ -546,7 +546,7 @@ function! s:do_align(todo, modes, all_tokens, all_delims, fl, ll, fc, lc, nth, r
     " Adjust indentation of the lines starting with a delimiter
     let lpad = ''
     if nth == 0
-      let ipad = repeat(' ', min_indent - len(token.ml))
+      let ipad = repeat(' ', min_indent - s:strwidth(token.ml))
       if mode ==? 'l'
         let token = ipad . token
       else
diff --git a/test/fixed.vader b/test/fixed.vader
index a41d11b..c89dff9 100644
--- a/test/fixed.vader
+++ b/test/fixed.vader
@@ -1,3 +1,6 @@
+Execute:
+  Save &tabstop
+
 Given (Table):
   |a|b|c|d|
   | -|-|>-|-|
@@ -40,3 +43,80 @@ Execute:
 Expect:
   a <|>b <|>c <|
   aa<|>bb<|>cc<|
+
+Given (Tab-indented code (#20)):
+  class MyUnitTest(unittest.TestCase):
+  	def test_base(self):
+  		n2f = {}
+  		n2v = {}
+  		f2v = {}
+  		n2gv = {}
+  		n2vt = {}
+
+Execute:
+  set tabstop=1
+  %EasyAlign=
+
+Expect:
+  class MyUnitTest(unittest.TestCase):
+  	def test_base(self):
+  		n2f  = {}
+  		n2v  = {}
+  		f2v  = {}
+  		n2gv = {}
+  		n2vt = {}
+
+Execute:
+  set tabstop=2
+  %EasyAlign=
+
+Expect:
+  class MyUnitTest(unittest.TestCase):
+  	def test_base(self):
+  		n2f  = {}
+  		n2v  = {}
+  		f2v  = {}
+  		n2gv = {}
+  		n2vt = {}
+
+Execute:
+  set tabstop=4
+  %EasyAlign=
+
+Expect:
+  class MyUnitTest(unittest.TestCase):
+  	def test_base(self):
+  		n2f  = {}
+  		n2v  = {}
+  		f2v  = {}
+  		n2gv = {}
+  		n2vt = {}
+
+Execute:
+  set tabstop=8
+  %EasyAlign=
+
+Expect:
+  class MyUnitTest(unittest.TestCase):
+  	def test_base(self):
+  		n2f  = {}
+  		n2v  = {}
+  		f2v  = {}
+  		n2gv = {}
+  		n2vt = {}
+
+Execute:
+  set tabstop=12
+  %EasyAlign=
+
+Expect:
+  class MyUnitTest(unittest.TestCase):
+  	def test_base(self):
+  		n2f  = {}
+  		n2v  = {}
+  		f2v  = {}
+  		n2gv = {}
+  		n2vt = {}
+
+Execute:
+  Restore
diff --git a/test/interactive.vader b/test/interactive.vader
index 11eecb1..8b884b8 100644
--- a/test/interactive.vader
+++ b/test/interactive.vader
@@ -2,7 +2,7 @@ Execute (Clean up test environment):
   Save g:easy_align_ignore_groups,     g:easy_align_ignore_unmatched
   Save g:easy_align_indentation,       g:easy_align_delimiter_align
   Save g:easy_align_interactive_modes, g:easy_align_bang_interactive_modes
-  Save g:easy_align_delimiters
+  Save g:easy_align_delimiters,        &tabstop
   Save mapleader
 
   " TODO: revert after test