diff --git a/autoload/airline/highlighter.vim b/autoload/airline/highlighter.vim
index f424f35..b811dfa 100644
--- a/autoload/airline/highlighter.vim
+++ b/autoload/airline/highlighter.vim
@@ -13,6 +13,44 @@ function! s:gui2cui(rgb, fallback)
   return rgb[0]+rgb[1]+rgb[2]
 endfunction
 
+function! s:get_syn(group, what)
+  " need to pass in mode, known to break on 7.3.547
+  let mode = has('gui_running') ? 'gui' : 'cterm'
+  let color = synIDattr(synIDtrans(hlID(a:group)), a:what, mode)
+  if empty(color) || color == -1
+    let color = synIDattr(synIDtrans(hlID('Normal')), a:what, mode)
+  endif
+  if empty(color) || color == -1
+    if has('gui_running')
+      let color = a:what ==# 'fg' ? '#000000' : '#FFFFFF'
+    else
+      let color = a:what ==# 'fg' ? 0 : 1
+    endif
+  endif
+  return color
+endfunction
+
+function! s:get_array(fg, bg, opts)
+  let fg = a:fg
+  let bg = a:bg
+  return has('gui_running')
+        \ ? [ fg, bg, '', '', join(a:opts, ',') ]
+        \ : [ '', '', fg, bg, join(a:opts, ',') ]
+endfunction
+
+function! airline#highlighter#get_highlight(group, ...)
+  let fg = s:get_syn(a:group, 'fg')
+  let bg = s:get_syn(a:group, 'bg')
+  let reverse = synIDattr(synIDtrans(hlID(a:group)), 'reverse', has('gui_running') ? 'gui' : 'term')
+  return reverse ? s:get_array(bg, fg, a:000) : s:get_array(fg, bg, a:000)
+endfunction
+
+function! airline#highlighter#get_highlight2(fg, bg, ...)
+  let fg = s:get_syn(a:fg[0], a:fg[1])
+  let bg = s:get_syn(a:bg[0], a:bg[1])
+  return s:get_array(fg, bg, a:000)
+endfunction
+
 function! airline#highlighter#exec(group, colors)
   let colors = a:colors
   if s:is_win32term
@@ -50,6 +88,7 @@ endfunction
 
 function! airline#highlighter#add_separator(from, to, inverse)
   let s:separators[a:from.a:to] = [a:from, a:to, a:inverse]
+  call <sid>exec_separator({}, a:from, a:to, a:inverse, '')
 endfunction
 
 function! airline#highlighter#highlight(modes)
diff --git a/autoload/airline/themes.vim b/autoload/airline/themes.vim
index 0d9158d..770b476 100644
--- a/autoload/airline/themes.vim
+++ b/autoload/airline/themes.vim
@@ -15,42 +15,12 @@ function! airline#themes#generate_color_map(section1, section2, section3, file)
       \ }
 endfunction
 
-function! s:get_syn(group, what)
-  " need to pass in mode, known to break on 7.3.547
-  let mode = has('gui_running') ? 'gui' : 'cterm'
-  let color = synIDattr(synIDtrans(hlID(a:group)), a:what, mode)
-  if empty(color) || color == -1
-    let color = synIDattr(synIDtrans(hlID('Normal')), a:what, mode)
-  endif
-  if empty(color) || color == -1
-    if has('gui_running')
-      let color = a:what ==# 'fg' ? '#000000' : '#FFFFFF'
-    else
-      let color = a:what ==# 'fg' ? 0 : 1
-    endif
-  endif
-  return color
-endfunction
-
-function! s:get_array(fg, bg, opts)
-  let fg = a:fg
-  let bg = a:bg
-  return has('gui_running')
-        \ ? [ fg, bg, '', '', join(a:opts, ',') ]
-        \ : [ '', '', fg, bg, join(a:opts, ',') ]
-endfunction
-
 function! airline#themes#get_highlight(group, ...)
-  let fg = s:get_syn(a:group, 'fg')
-  let bg = s:get_syn(a:group, 'bg')
-  let reverse = synIDattr(synIDtrans(hlID(a:group)), 'reverse', has('gui_running') ? 'gui' : 'term')
-  return reverse ? s:get_array(bg, fg, a:000) : s:get_array(fg, bg, a:000)
+  return call('airline#highlighter#get_highlight', [a:group] + a:000)
 endfunction
 
 function! airline#themes#get_highlight2(fg, bg, ...)
-  let fg = s:get_syn(a:fg[0], a:fg[1])
-  let bg = s:get_syn(a:bg[0], a:bg[1])
-  return s:get_array(fg, bg, a:000)
+  return call('airline#highlighter#get_highlight2', [a:fg, a:bg] + a:000)
 endfunction
 
 function! airline#themes#patch(palette)
diff --git a/t/highligher.vim b/t/highligher.vim
new file mode 100644
index 0000000..658e816
--- /dev/null
+++ b/t/highligher.vim
@@ -0,0 +1,10 @@
+describe 'highlighter'
+  it 'should create separator highlight groups'
+    hi Foo1 ctermfg=1 ctermbg=2
+    hi Foo2 ctermfg=3 ctermbg=4
+    call airline#highlighter#add_separator('Foo1', 'Foo2', 0)
+    let hl = airline#highlighter#get_highlight('Foo1_to_Foo2')
+    Expect hl == [ '', '', '4', '2', '' ]
+  end
+end
+
diff --git a/t/themes.vim b/t/themes.vim
index d37c8fa..cc814ab 100644
--- a/t/themes.vim
+++ b/t/themes.vim
@@ -25,5 +25,13 @@ describe 'themes'
     Expect colors[2] == '222'
     Expect colors[3] == '103'
   end
+
+  it 'should pass args through correctly'
+    let hl = airline#themes#get_highlight('Foo', 'bold', 'italic')
+    Expect hl == ['', '', 0, 1, 'bold,italic']
+
+    let hl = airline#themes#get_highlight2(['Foo','bg'], ['Foo','fg'], 'italic', 'bold')
+    Expect hl == ['', '', 1, 0, 'italic,bold']
+  end
 end