diff --git a/lib_test/dune b/lib_test/dune
index 2130f05f..27bffb04 100644
--- a/lib_test/dune
+++ b/lib_test/dune
@@ -1,7 +1,7 @@
 (tests
  (libraries re fort_unit)
  (modules :standard \ test_str)
- (names test_easy test_re test_perl test_emacs test_glob test_pcre))
+ (names test_easy test_re test_perl test_emacs test_glob test_pcre test_posix))
 
 (test
  (libraries re fort_unit str)
diff --git a/lib_test/test_posix.ml b/lib_test/test_posix.ml
new file mode 100644
index 00000000..b8c99bc9
--- /dev/null
+++ b/lib_test/test_posix.ml
@@ -0,0 +1,12 @@
+open OUnit
+
+let test_class_space () =
+  let (_ : Re.re) = Re.Posix.compile_pat {|a[[:space:]]b|} in
+  ()
+
+let suite = "posix" >:::
+  [ "regression 213" >:: test_class_space
+  ]
+
+let () =
+  ignore (run_test_tt_main suite)