diff --git a/src/hb-common.cc b/src/hb-common.cc
index 49f3eb8..a223edb 100644
--- a/src/hb-common.cc
+++ b/src/hb-common.cc
@@ -33,6 +33,8 @@
 #include "hb-mutex-private.hh"
 #include "hb-object-private.hh"
 
+#include <locale.h>
+
 HB_BEGIN_DECLS
 
 
@@ -179,6 +181,25 @@
   return language->s;
 }
 
+hb_language_t
+hb_language_get_default (void)
+{
+  static hb_language_t default_language;
+
+  if (!default_language) {
+    /* This block is not quite threadsafe, but is not as bad as
+     * it looks since it's idempotent.  As long as pointer ops
+     * are atomic, we are safe. */
+
+    /* I hear that setlocale() doesn't honor env vars on Windows,
+     * but for now we ignore that. */
+
+    default_language = hb_language_from_string (setlocale (LC_CTYPE, NULL));
+  }
+
+  return default_language;
+}
+
 
 /* hb_script_t */
 
diff --git a/src/hb-common.h b/src/hb-common.h
index 64109da..9546b21 100644
--- a/src/hb-common.h
+++ b/src/hb-common.h
@@ -113,6 +113,9 @@
 const char *
 hb_language_to_string (hb_language_t language);
 
+hb_language_t
+hb_language_get_default (void);
+
 
 /* hb_unicode_general_category_t */
 
diff --git a/src/hb-shape.cc b/src/hb-shape.cc
index cc711ea..fccb81e 100644
--- a/src/hb-shape.cc
+++ b/src/hb-shape.cc
@@ -81,7 +81,7 @@
   /* If language is not set, use default language from locale */
   if (buffer->props.language == NULL) {
     /* TODO get_default_for_script? using $LANGUAGE */
-    //buffer->props.language = hb_language_get_default ();
+    buffer->props.language = hb_language_get_default ();
   }
 
   hb_shape_internal (font, buffer, features, num_features);
diff --git a/test/test-common.c b/test/test-common.c
index c2b4e1c..c1e3175 100644
--- a/test/test-common.c
+++ b/test/test-common.c
@@ -169,6 +169,11 @@
 
   g_assert (NULL == hb_language_from_string (NULL));
   g_assert (NULL == hb_language_from_string (""));
+
+  /* Not sure how to test this better.  Setting env vars
+   * here doesn't sound like the right approach, and I'm
+   * not sure that it even works. */
+  g_assert (NULL != hb_language_get_default ());
 }
 
 int