diff --git a/test/unique.vim b/test/unique.vim
new file mode 100644
index 0000000..8bea52d
--- /dev/null
+++ b/test/unique.vim
@@ -0,0 +1,34 @@
+let s:suite = themis#suite('unique')
+let s:assert = themis#helper('assert')
+
+function! s:unique(...)
+  return call(SID('unique'), a:000)
+endfunction
+
+function! s:suite.nil()
+  call s:assert.equals(s:unique([]), [])
+endfunction
+
+function! s:suite.one()
+  call s:assert.equals(s:unique(['foo']), ['foo'])
+endfunction
+
+function! s:suite.two()
+  call s:assert.equals(s:unique(['foo', 'bar']), ['foo', 'bar'])
+endfunction
+
+function! s:suite.three()
+  call s:assert.equals(s:unique(['foo', 'bar', 'baz']), ['foo', 'bar', 'baz'])
+endfunction
+
+function! s:suite.two_duplicated()
+  call s:assert.equals(s:unique(['foo', 'foo']), ['foo'])
+endfunction
+
+function! s:suite.three_duplicated()
+  call s:assert.equals(s:unique(['foo', 'bar', 'foo']), ['foo', 'bar'])
+endfunction
+
+function! s:suite.many()
+  call s:assert.equals(s:unique(['foo', 'bar', 'foo', 'baz', 'baz', 'qux', 'foo']), ['foo', 'bar', 'baz', 'qux'])
+endfunction