diff --git a/GNUmakefile b/GNUmakefile
index dc0959b..1e50073 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -44,7 +44,7 @@ libobjc_C_FILES = \
 libobjcxx_CC_FILES = objcxx_eh.cc
 libobjcxx_LDFLAGS = -L./obj/$(GNUSTEP_TARGET_LDIR)/ -lstdc++ -lobjc
 
-ifneq ($(enable_legacy), no)
+ifeq ($(disable_legacy), yes)
 libobjc_C_FILES += legacy_malloc.c
 libobjc_CPPFLAGS += -DNO_LEGACY
 endif
diff --git a/NSBlocks.m b/NSBlocks.m
index 223d900..a469e46 100644
--- a/NSBlocks.m
+++ b/NSBlocks.m
@@ -21,16 +21,16 @@ static void createNSBlockSubclass(Class superclass, Class newClass,
 	//metaClass->class_pointer = superclass->class_pointer;
 	//metaClass->super_class = superclass->class_pointer;
 	metaClass->info = objc_class_flag_meta;
-	metaClass->dtable = __objc_uninstalled_dtable;
+	metaClass->dtable = uninstalled_dtable;
 
 	// Set up the new class
 	newClass->isa = metaClass;
 	newClass->super_class = (Class)superclass->name;
 	newClass->name = name;
 	newClass->info = objc_class_flag_class;
-	newClass->dtable = __objc_uninstalled_dtable;
+	newClass->dtable = uninstalled_dtable;
 
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 	class_table_insert(newClass);
 
 }
diff --git a/alias_table.c b/alias_table.c
index cf2c148..ed39040 100644
--- a/alias_table.c
+++ b/alias_table.c
@@ -62,7 +62,7 @@ static alias_table_internal_table *alias_table;
 #include "pool.h"
 
 
-PRIVATE void __objc_init_alias_table(void)
+PRIVATE void init_alias_table(void)
 {
 	alias_table = alias_table_internal_create(128);
 }
diff --git a/class_table.c b/class_table.c
index 6bc5697..9c261d2 100644
--- a/class_table.c
+++ b/class_table.c
@@ -132,7 +132,7 @@ PRIVATE Class class_table_next(void **e)
 			(struct class_table_internal_table_enumerator**)e);
 }
 
-PRIVATE void __objc_init_class_tables(void)
+PRIVATE void init_class_tables(void)
 {
 	class_table = class_table_internal_create(4096);
 	objc_init_load_messages_table();
@@ -248,7 +248,7 @@ PRIVATE BOOL objc_resolve_class(Class cls)
 
 PRIVATE void objc_resolve_class_links(void)
 {
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 	Class class = unresolved_class_list;
 	BOOL resolvedClass;
 	do
@@ -347,8 +347,8 @@ static void reload_class(struct objc_class *class, struct objc_class *old)
 	objc_register_selectors_from_class(class->isa);
 
 	// Set the uninstalled dtable.  The compiler could do this as well.
-	class->dtable = __objc_uninstalled_dtable;
-	class->isa->dtable = __objc_uninstalled_dtable;
+	class->dtable = uninstalled_dtable;
+	class->isa->dtable = uninstalled_dtable;
 
 	// If this is a root class, make the class into the metaclass's superclass.
 	// This means that all instance methods will be available to the class.
@@ -401,8 +401,8 @@ PRIVATE void objc_load_class(struct objc_class *class)
 	objc_register_selectors_from_class(class->isa);
 
 	// Set the uninstalled dtable.  The compiler could do this as well.
-	class->dtable = __objc_uninstalled_dtable;
-	class->isa->dtable = __objc_uninstalled_dtable;
+	class->dtable = uninstalled_dtable;
+	class->isa->dtable = uninstalled_dtable;
 
 	// If this is a root class, make the class into the metaclass's superclass.
 	// This means that all instance methods will be available to the class.
diff --git a/dtable.c b/dtable.c
index 57f0125..899b3d9 100644
--- a/dtable.c
+++ b/dtable.c
@@ -10,7 +10,7 @@
 #include "dtable.h"
 #include "visibility.h"
 
-PRIVATE dtable_t __objc_uninstalled_dtable;
+PRIVATE dtable_t uninstalled_dtable;
 
 /** Head of the list of temporary dtables.  Protected by initialize_lock. */
 PRIVATE InitializingDtable *temporary_dtables;
@@ -56,14 +56,14 @@ struct objc_dtable
 	mutex_t lock;
 };
 
-PRIVATE void __objc_init_dispatch_tables ()
+PRIVATE void init_dispatch_tables ()
 {
 	INIT_LOCK(initialize_lock);
 }
 
 Class class_getSuperclass(Class);
 
-PRIVATE void __objc_update_dispatch_table_for_class(Class cls)
+PRIVATE void update_dispatch_table_for_class(Class cls)
 {
 	static BOOL warned = NO;
 	if (!warned)
@@ -79,7 +79,7 @@ static dtable_t create_dtable_for_class(Class class)
 	// Don't create a dtable for a class that already has one
 	if (classHasDtable(class)) { return dtable_for_class(class); }
 
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 
 	// Make sure that another thread didn't create the dtable while we were
 	// waiting on the lock.
@@ -231,7 +231,7 @@ PRIVATE void objc_update_dtable_for_class(Class cls)
 	// need to access it
 	if ((NULL == dtable) || (NULL == dtable->slots)) { return; }
 
-	LOCK_UNTIL_RETURN(&dtable->lock);
+	LOCK_FOR_SCOPE(&dtable->lock);
 
 	update_dtable(dtable);
 
@@ -248,7 +248,7 @@ PRIVATE struct objc_slot* objc_dtable_lookup(dtable_t dtable, uint32_t uid)
 		return slot;
 	}
 
-	LOCK_UNTIL_RETURN(&dtable->lock);
+	LOCK_FOR_SCOPE(&dtable->lock);
 	if (NULL == dtable->slots)
 	{
 		update_dtable(dtable);
@@ -285,10 +285,10 @@ PRIVATE dtable_t objc_copy_dtable_for_class(dtable_t old, Class cls)
 #else
 
 
-PRIVATE void __objc_init_dispatch_tables ()
+PRIVATE void init_dispatch_tables ()
 {
 	INIT_LOCK(initialize_lock);
-	__objc_uninstalled_dtable = SparseArrayNewWithDepth(dtable_depth);
+	uninstalled_dtable = SparseArrayNewWithDepth(dtable_depth);
 }
 
 static BOOL installMethodInDtable(Class class,
@@ -297,7 +297,7 @@ static BOOL installMethodInDtable(Class class,
                                   struct objc_method *method,
                                   BOOL replaceExisting)
 {
-	assert(__objc_uninstalled_dtable != dtable);
+	assert(uninstalled_dtable != dtable);
 	uint32_t sel_id = method->selector->index;
 	struct objc_slot *slot = SparseArrayLookup(dtable, sel_id);
 	if (NULL != slot)
@@ -357,7 +357,7 @@ static void installMethodsInClass(Class cls,
                                   BOOL replaceExisting)
 {
 	SparseArray *dtable = dtable_for_class(cls);
-	assert(__objc_uninstalled_dtable != dtable);
+	assert(uninstalled_dtable != dtable);
 
 	uint32_t idx = 0;
 	struct objc_method *m;
@@ -400,7 +400,7 @@ PRIVATE void objc_update_dtable_for_class(Class cls)
 	if (!classHasDtable(cls)) { return; }
 	//fprintf(stderr, "Updating dtable for %s\n", cls->name);
 
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 
 	//fprintf(stderr, "Adding methods to %s\n", cls->name);
 	SparseArray *methods = SparseArrayNewWithDepth(dtable_depth);
@@ -410,7 +410,7 @@ PRIVATE void objc_update_dtable_for_class(Class cls)
 	mergeMethodsFromSuperclass(cls, cls, methods);
 	SparseArrayDestroy(methods);
 }
-PRIVATE void __objc_update_dispatch_table_for_class(Class cls)
+PRIVATE void update_dispatch_table_for_class(Class cls)
 {
 	static BOOL warned = NO;
 	if (!warned)
@@ -427,7 +427,7 @@ static SparseArray *create_dtable_for_class(Class class)
 	// Don't create a dtable for a class that already has one
 	if (classHasDtable(class)) { return dtable_for_class(class); }
 
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 
 	// Make sure that another thread didn't create the dtable while we were
 	// waiting on the lock.
@@ -444,7 +444,7 @@ static SparseArray *create_dtable_for_class(Class class)
 	else
 	{
 		dtable_t super_dtable = dtable_for_class(super);
-		if (super_dtable == __objc_uninstalled_dtable)
+		if (super_dtable == uninstalled_dtable)
 		{
 			super_dtable = create_dtable_for_class(super);
 		}
@@ -478,19 +478,19 @@ PRIVATE void objc_resize_dtables(uint32_t newSize)
 	// If dtables already have enough space to store all registered selectors, do nothing
 	if (1<<dtable_depth > newSize) { return; }
 
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 
 	dtable_depth <<= 1;
 
-	uint32_t oldMask = __objc_uninstalled_dtable->mask;
+	uint32_t oldMask = uninstalled_dtable->mask;
 
-	SparseArrayExpandingArray(__objc_uninstalled_dtable);
+	SparseArrayExpandingArray(uninstalled_dtable);
 	// Resize all existing dtables
 	void *e = NULL;
 	struct objc_class *next;
 	while ((next = class_table_next(&e)))
 	{
-		if (next->dtable != (void*)__objc_uninstalled_dtable && 
+		if (next->dtable != (void*)uninstalled_dtable && 
 			NULL != next->dtable &&
 			((SparseArray*)next->dtable)->mask == oldMask)
 		{
@@ -532,7 +532,7 @@ PRIVATE void objc_send_initialize(id object)
 	// NOTE: Ideally, we would actually lock on the class object using
 	// objc_sync_enter().  This should be fixed once sync.m contains a (fast)
 	// special case for classes.
-	LOCK_UNTIL_RETURN(&initialize_lock);
+	LOCK_FOR_SCOPE(&initialize_lock);
 
 	// Make sure that the class is resolved.
 	objc_resolve_class(class);
diff --git a/dtable.h b/dtable.h
index bf2e792..8b670f1 100644
--- a/dtable.h
+++ b/dtable.h
@@ -2,6 +2,7 @@
 #include "class.h"
 #include "sarray2.h"
 #include "objc/slot.h"
+#include "visibility.h"
 #include <stdint.h>
 
 #ifdef __OBJC_LOW_MEMORY__
@@ -15,7 +16,7 @@ typedef SparseArray* dtable_t;
 /**
  * Pointer to the sparse array representing the pretend (uninstalled) dtable.
  */
-extern dtable_t __objc_uninstalled_dtable;
+PRIVATE extern dtable_t uninstalled_dtable;
 /**
  * Structure for maintaining a linked list of temporary dtables.  When sending
  * an +initialize message to a class, we create a temporary dtables and store
@@ -41,7 +42,7 @@ extern mutex_t initialize_lock;
  */
 static inline int classHasInstalledDtable(struct objc_class *cls)
 {
-	return (cls->dtable != __objc_uninstalled_dtable);
+	return (cls->dtable != uninstalled_dtable);
 }
 
 /**
@@ -55,7 +56,7 @@ static inline dtable_t dtable_for_class(Class cls)
 	{
 		return cls->dtable;
 	}
-	LOCK_UNTIL_RETURN(&initialize_lock);
+	LOCK_FOR_SCOPE(&initialize_lock);
 	if (classHasInstalledDtable(cls))
 	{
 		return cls->dtable;
@@ -64,7 +65,7 @@ static inline dtable_t dtable_for_class(Class cls)
 	* O(n) where n is the number of +initialize methods on the stack.  In
 	* practice, this is a very small number.  Profiling with GNUstep showed that
 	* this peaks at 8. */
-	dtable_t dtable = __objc_uninstalled_dtable;
+	dtable_t dtable = uninstalled_dtable;
 	InitializingDtable *buffer = temporary_dtables;
 	while (NULL != buffer)
 	{
@@ -77,7 +78,7 @@ static inline dtable_t dtable_for_class(Class cls)
 	}
 	if (dtable == 0)
 	{
-		dtable = __objc_uninstalled_dtable;
+		dtable = uninstalled_dtable;
 	}
 	return dtable;
 }
@@ -88,7 +89,7 @@ static inline dtable_t dtable_for_class(Class cls)
  */
 static inline int classHasDtable(struct objc_class *cls)
 {
-	return (dtable_for_class(cls) != __objc_uninstalled_dtable);
+	return (dtable_for_class(cls) != uninstalled_dtable);
 }
 
 /**
diff --git a/hash_table.c b/hash_table.c
index 0cd5f4f..47b4582 100644
--- a/hash_table.c
+++ b/hash_table.c
@@ -9,12 +9,11 @@ PRIVATE void objc_collect_garbage_data(void(*cleanup)(void*), void *garbage)
 {
 	if (0 == garbage_queue)
 	{
-		LOCK(__objc_runtime_mutex);
+		LOCK_RUNTIME_FOR_SCOPE();
 		if (0 == garbage_queue)
 		{
 			garbage_queue = dispatch_queue_create("ObjC deferred free queue", 0);
 		}
-		UNLOCK(__objc_runtime_mutex);
 	}
 	dispatch_async_f(garbage_queue, garbage, cleanup);
 }
diff --git a/loader.c b/loader.c
index 149efbc..dd55581 100644
--- a/loader.c
+++ b/loader.c
@@ -3,19 +3,20 @@
 #include "objc/runtime.h"
 #include "lock.h"
 #include "loader.h"
+#include "visibility.h"
 
 /**
  * Runtime lock.  This is exposed in 
  */
-static mutex_t objc_runtime_mutex;
-void *__objc_runtime_mutex = &objc_runtime_mutex;
+PRIVATE mutex_t runtime_mutex;
+LEGACY void *__objc_runtime_mutex = &runtime_mutex;
 
-void __objc_sync_init(void);
-void __objc_init_selector_tables(void);
-void __objc_init_protocol_table(void);
-void __objc_init_class_tables(void);
-void __objc_init_dispatch_tables(void);
-void __objc_init_alias_table(void);
+void sync_init(void);
+void init_selector_tables(void);
+void init_protocol_table(void);
+void init_class_tables(void);
+void init_dispatch_tables(void);
+void init_alias_table(void);
 void objc_send_load_message(Class class);
 
 /* Number of threads that are alive.  */
@@ -42,23 +43,23 @@ void __objc_exec_class(struct objc_module_abi_8 *module)
 		// pure-C main() function spawns two threads which then, concurrently,
 		// call dlopen() or equivalent, and the platform's implementation of
 		// this does not perform any synchronization.
-		INIT_LOCK(objc_runtime_mutex);
+		INIT_LOCK(runtime_mutex);
 		// Create the lock used to protect the creation of hidden classes by
 		// @synchronized()
-		__objc_sync_init();
+		sync_init();
 
 		// Create the various tables that the runtime needs.
-		__objc_init_selector_tables();
-		__objc_init_protocol_table();
-		__objc_init_class_tables();
-		__objc_init_dispatch_tables();
-		__objc_init_alias_table();
+		init_selector_tables();
+		init_protocol_table();
+		init_class_tables();
+		init_dispatch_tables();
+		init_alias_table();
 		first_run = NO;
 	}
 
 	// The runtime mutex is held for the entire duration of a load.  It does
 	// not need to be acquired or released in any of the called load functions.
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 
 	struct objc_symbol_table_abi_8 *symbols = module->symbol_table;
 	// Register all of the selectors used in this module.
diff --git a/lock.h b/lock.h
index 59ed3fa..3d9e70f 100644
--- a/lock.h
+++ b/lock.h
@@ -6,7 +6,6 @@
 
 #ifndef __LIBOBJC_LOCK_H_INCLUDED__
 #define __LIBOBJC_LOCK_H_INCLUDED__
-
 #ifdef WIN32
 #	include <windows.h>
 typedef HANDLE mutex_t;
@@ -52,7 +51,7 @@ __attribute__((unused)) static void objc_release_lock(void *x)
  * Acquires the lock and automatically releases it at the end of the current
  * scope.
  */
-#define LOCK_UNTIL_RETURN(lock) \
+#define LOCK_FOR_SCOPE(lock) \
 	__attribute__((cleanup(objc_release_lock)))\
 	__attribute__((unused)) mutex_t *lock_pointer = lock;\
 	LOCK(lock)
@@ -60,6 +59,10 @@ __attribute__((unused)) static void objc_release_lock(void *x)
 /**
  * The global runtime mutex.
  */
-extern void *__objc_runtime_mutex;
+extern mutex_t runtime_mutex;
+
+#define LOCK_RUNTIME() LOCK(&runtime_mutex)
+#define UNLOCK_RUNTIME() UNLOCK(&runtime_mutex)
+#define LOCK_RUNTIME_FOR_SCOPE() LOCK_FOR_SCOPE(&runtime_mutex)
 
 #endif // __LIBOBJC_LOCK_H_INCLUDED__
diff --git a/protocol.c b/protocol.c
index 316bba1..f8bfbd5 100644
--- a/protocol.c
+++ b/protocol.c
@@ -29,7 +29,7 @@ static int protocol_hash(const struct objc_protocol2 *protocol)
 
 static protocol_table *known_protocol_table;
 
-void __objc_init_protocol_table(void)
+void init_protocol_table(void)
 {
 	known_protocol_table = protocol_create(128);
 }  
diff --git a/runtime.c b/runtime.c
index b54237f..350f202 100644
--- a/runtime.c
+++ b/runtime.c
@@ -559,10 +559,11 @@ void objc_disposeClassPair(Class cls)
 	Class meta = ((id)cls)->isa;
 	// Remove from the runtime system so nothing tries updating the dtable
 	// while we are freeing the class.
-	LOCK(__objc_runtime_mutex);
-	safe_remove_from_subclass_list(meta);
-	safe_remove_from_subclass_list(cls);
-	UNLOCK(__objc_runtime_mutex);
+	{
+		LOCK_RUNTIME_FOR_SCOPE();
+		safe_remove_from_subclass_list(meta);
+		safe_remove_from_subclass_list(cls);
+	}
 
 	// Free the method and ivar lists.
 	freeMethodLists(cls);
@@ -594,7 +595,7 @@ Class objc_allocateClassPair(Class superclass, const char *name, size_t extraByt
 	metaClass->name = strdup(name);
 	metaClass->info = objc_class_flag_meta | objc_class_flag_user_created |
 		objc_class_flag_new_abi;
-	metaClass->dtable = __objc_uninstalled_dtable;
+	metaClass->dtable = uninstalled_dtable;
 	metaClass->instance_size = sizeof(struct objc_class);
 
 	// Set up the new class
@@ -605,7 +606,7 @@ Class objc_allocateClassPair(Class superclass, const char *name, size_t extraByt
 	newClass->name = strdup(name);
 	newClass->info = objc_class_flag_class | objc_class_flag_user_created |
 		objc_class_flag_new_abi;
-	newClass->dtable = __objc_uninstalled_dtable;
+	newClass->dtable = uninstalled_dtable;
 	newClass->instance_size = superclass->instance_size;
 
 	return newClass;
@@ -658,6 +659,6 @@ const char *object_getClassName(id obj)
 
 void objc_registerClassPair(Class cls)
 {
-	LOCK_UNTIL_RETURN(__objc_runtime_mutex);
+	LOCK_RUNTIME_FOR_SCOPE();
 	class_table_insert(cls);
 }
diff --git a/selector_table.c b/selector_table.c
index dad5d27..9add1f1 100644
--- a/selector_table.c
+++ b/selector_table.c
@@ -220,7 +220,7 @@ void objc_resize_dtables(uint32_t);
 /**
  * Create data structures to store selectors.
  */
-PRIVATE void __objc_init_selector_tables()
+PRIVATE void init_selector_tables()
 {
 	selector_list = SparseArrayNew();
 	INIT_LOCK(selector_table_lock);
@@ -329,7 +329,7 @@ static SEL objc_register_selector_copy(SEL aSel, BOOL copyArgs)
 	//fprintf(stderr, "Not adding new copy\n");
 		return copy;
 	}
-	LOCK_UNTIL_RETURN(&selector_table_lock);
+	LOCK_FOR_SCOPE(&selector_table_lock);
 	copy = selector_lookup(aSel->name, aSel->types);
 	if (NULL != copy && selector_identical(aSel, copy))
 	{
@@ -516,7 +516,7 @@ PRIVATE void objc_register_selector_array(SEL selectors, unsigned long count)
  * All of the functions in this section are deprecated and should not be used
  * in new code.
  */
-#ifdef NO_LEGACY
+#ifndef NO_LEGACY
 SEL sel_get_typed_uid (const char *name, const char *types)
 {
 	if (NULL == name) { return NULL; }
@@ -592,45 +592,3 @@ BOOL sel_eq(SEL s1, SEL s2)
 }
 
 #endif // NO_LEGACY
-
-/*
- * Some simple sanity tests.
- */
-#ifdef SEL_TEST
-static void logSelector(SEL sel)
-{
-	fprintf(stderr, "%s = {%p, %s}\n", sel_getNameNonUnique(sel), sel->name, sel_getType_np(sel));
-}
-void objc_resize_dtables(uint32_t ignored) {}
-
-int main(void)
-{
-	__objc_init_selector_tables();
-	SEL a = sel_registerTypedName_np("foo:", "1234");
-	logSelector(a);
-	a = sel_registerName("bar:");
-	a = sel_registerName("foo:");
-	logSelector(a);
-	logSelector(sel_get_any_typed_uid("foo:"));
-	a = sel_registerTypedName_np("foo:", "1234");
-	logSelector(a);
-	logSelector(sel_get_any_typed_uid("foo:"));
-	a = sel_registerTypedName_np("foo:", "456");
-	logSelector(a);
-	unsigned count = sel_copyTypes("foo:", NULL, 0);
-	const char *types[count];
-	sel_copyTypes("foo:", types, count);
-	for (unsigned i=0 ; i<count ; i++)
-	{
-		fprintf(stderr, "Found type %s\n", types[i]);
-	}
-	uint32_t idx=0;
-	struct sel_type_list *type;
-	while ((type= SparseArrayNext(selector_list, &idx)))
-	{
-		fprintf(stderr, "Idx: %d, sel: %s (%s)\n", idx, type->value, ((struct sel_type_list *)SparseArrayLookup(selector_list, idx))->value);
-	}
-	fprintf(stderr, "Number of types: %d\n", count);
-	SEL sel;
-}
-#endif
diff --git a/sendmsg2.c b/sendmsg2.c
index 51f98cb..ce43c75 100644
--- a/sendmsg2.c
+++ b/sendmsg2.c
@@ -63,7 +63,7 @@ retry:;
 		Class class = (*receiver)->isa;
 		dtable_t dtable = dtable_for_class(class);
 		/* Install the dtable if it hasn't already been initialized. */
-		if (dtable == __objc_uninstalled_dtable)
+		if (dtable == uninstalled_dtable)
 		{
 			objc_send_initialize(*receiver);
 			dtable = dtable_for_class(class);
@@ -157,7 +157,7 @@ Slot_t objc_slot_lookup_super(struct objc_super *super, SEL selector)
 		if (0 == result)
 		{
 			// Dtable should always be installed in the superclass
-			assert(dtable_for_class(class) != __objc_uninstalled_dtable);
+			assert(dtable_for_class(class) != uninstalled_dtable);
 			result = &nil_slot;
 		}
 		return result;
@@ -192,7 +192,7 @@ struct profile_info
 	IMP method;
 };
 
-static void __objc_profile_init(void)
+static void profile_init(void)
 {
 	INIT_LOCK(profileLock);
 	profileSymbols = fopen("objc_profile.symbols", "a");
@@ -207,12 +207,11 @@ void objc_profile_write_symbols(char **symbols)
 {
 	if (NULL == profileData)
 	{
-		LOCK(__objc_runtime_mutex);
+		LOCK_RUNTIME_FOR_SCOPE();
 		if (NULL == profileData)
 		{
-			__objc_profile_init();
+			profile_init();
 		}
-		UNLOCK(__objc_runtime_mutex);
 	}
 	LOCK(&profileLock);
 	while(*symbols)
@@ -239,12 +238,11 @@ void objc_msg_profile(id receiver, IMP method,
 	// when we are not profiling.
 	if (NULL == profileData)
 	{
-		LOCK(__objc_runtime_mutex);
+		LOCK_RUNTIME_FOR_SCOPE();
 		if (NULL == profileData)
 		{
-			__objc_profile_init();
+			profile_init();
 		}
-		UNLOCK(__objc_runtime_mutex);
 	}
 	struct profile_info profile_data = { module, callsite, method };
 	fwrite(&profile_data, sizeof(profile_data), 1, profileData);
@@ -260,7 +258,7 @@ Slot_t objc_get_slot(Class cls, SEL selector)
 	{
 		void *dtable = dtable_for_class(cls);
 		/* Install the dtable if it hasn't already been initialized. */
-		if (dtable == __objc_uninstalled_dtable)
+		if (dtable == uninstalled_dtable)
 		{
 			//objc_send_initialize((id)cls);
 			dtable = dtable_for_class(cls);
@@ -316,6 +314,7 @@ IMP class_getMethodImplementation_stret(Class cls, SEL name)
 // Legacy compatibility
 ////////////////////////////////////////////////////////////////////////////////
 
+#ifndef NO_LEGACY
 /**
  * Legacy message lookup function.
  */
@@ -328,6 +327,17 @@ IMP get_imp(Class cls, SEL selector)
 {
 	return class_getMethodImplementation(cls, selector);
 }
+
+/**
+ * Message send function that only ever worked on a small subset of compiler /
+ * architecture combinations.
+ */
+void *objc_msg_sendv(void)
+{
+	fprintf(stderr, "objc_msg_sendv() never worked correctly.  Don't use it.\n");
+	abort();
+}
+#endif
 /**
  * Legacy message lookup function.  Does not support fast proxies or safe IMP
  * caching.
@@ -349,12 +359,3 @@ IMP objc_msg_lookup_super(struct objc_super *super, SEL selector)
 {
 	return objc_slot_lookup_super(super, selector)->method;
 }
-/**
- * Message send function that only ever worked on a small subset of compiler /
- * architecture combinations.
- */
-void *objc_msg_sendv(void)
-{
-	fprintf(stderr, "objc_msg_sendv() never worked correctly.  Don't use it.\n");
-	abort();
-}
diff --git a/sync.m b/sync.m
index 634f0a3..57c9f2a 100644
--- a/sync.m
+++ b/sync.m
@@ -20,7 +20,7 @@ int snprintf(char *restrict s, size_t n, const char *restrict format, ...);
 
 static mutex_t at_sync_init_lock;
 
-void __objc_sync_init(void)
+PRIVATE void sync_init(void)
 {
 	INIT_LOCK(at_sync_init_lock);
 }
diff --git a/visibility.h b/visibility.h
index 6521dec..33f653b 100644
--- a/visibility.h
+++ b/visibility.h
@@ -5,4 +5,9 @@
 #	define PUBLIC __attribute__ ((visibility("default")))
 #	define PRIVATE  __attribute__ ((visibility("hidden")))
 #endif
+#ifdef NO_LEGACY
+#	define LEGACY PRIVATE
+#else
+#	define LEGACY PUBLIC
+#endif