diff --git a/libobjc/ChangeLog b/libobjc/ChangeLog
index f88f2f45cdf..dbc70f190bb 100644
--- a/libobjc/ChangeLog
+++ b/libobjc/ChangeLog
@@ -1,3 +1,18 @@
+2011-10-09  Nicola Pero  <nicola.pero@meta-innovation.com>
+
+	PR libobjc/49883
+	* init.c (__objc_exec_class): Work around a bug in clang's code
+	generation.  Clang sets the class->info field to values different
+	from 0x1 or 0x2 (the only allowed values in the traditional GNU
+	Objective-C runtime ABI) to store some additional information, but
+	this breaks backwards compatibility.  Wipe out all the bits in the
+	fields other than the first two upon loading a class.
+
+2011-10-09  Nicola Pero  <nicola.pero@meta-innovation.com>
+	
+	* class.c (objc_lookup_class): Added back for compatibility with
+	clang which seems to emit calls to it.
+
 2011-10-08  Richard Frith-Macdonald <rfm@gnu.org>
             Nicola Pero  <nicola.pero@meta-innovation.com>
 
diff --git a/libobjc/class.c b/libobjc/class.c
index edc56aa9ec4..3b750829f3b 100644
--- a/libobjc/class.c
+++ b/libobjc/class.c
@@ -764,6 +764,15 @@ objc_get_meta_class (const char *name)
   return objc_get_class (name)->class_pointer;
 }
 
+/* This is not used by GCC, but the clang compiler seems to use it
+   when targetting the GNU runtime.  That's wrong, but we have it to
+   be compatible.  */
+Class
+objc_lookup_class (const char *name)
+{
+  return objc_getClass (name);
+}
+
 /* This is used when the implementation of a method changes.  It goes
    through all classes, looking for the ones that have these methods
    (either method_a or method_b; method_b can be NULL), and reloads
diff --git a/libobjc/init.c b/libobjc/init.c
index d4475b3b787..23ba41ba128 100644
--- a/libobjc/init.c
+++ b/libobjc/init.c
@@ -643,6 +643,15 @@ __objc_exec_class (struct objc_module *module)
       assert (CLS_ISMETA (class->class_pointer));
       DEBUG_PRINTF (" installing class '%s'\n", class->name);
 
+      /* Workaround for a bug in clang: Clang may set flags other than
+	 _CLS_CLASS and _CLS_META even when compiling for the
+	 traditional ABI (version 8), confusing our runtime.  Try to
+	 wipe these flags out.  */
+      if (CLS_ISCLASS (class))
+	__CLS_INFO (class) = _CLS_CLASS;
+      else
+	__CLS_INFO (class) = _CLS_META;
+
       /* Initialize the subclass list to be NULL.  In some cases it
 	 isn't and this crashes the program.  */
       class->subclass_list = NULL;