Index: src/OFObject.m
==================================================================
--- src/OFObject.m
+++ src/OFObject.m
@@ -119,11 +119,14 @@
 	((struct pre_ivar*)instance)->memchunks = NULL;
 	((struct pre_ivar*)instance)->memchunks_size = 0;
 	((struct pre_ivar*)instance)->retain_count = 1;
 
 #ifndef OF_ATOMIC_OPS
-	of_spinlock_new(&((struct pre_ivar*)instance)->retain_spinlock);
+	if (!of_spinlock_new(&((struct pre_ivar*)instance)->retain_spinlock)) {
+		free(instance);
+		@throw [OFInitializationFailedException newWithClass: self];
+	}
 #endif
 
 	instance = (OFObject*)((char*)instance + PRE_IVAR_ALIGN);
 	memset(instance, 0, isize);
 	instance->isa = self;
@@ -499,13 +502,13 @@
 - retain
 {
 #ifdef OF_ATOMIC_OPS
 	of_atomic_inc32(&PRE_IVAR->retain_count);
 #else
-	of_spinlock_lock(&PRE_IVAR->retain_spinlock);
+	assert(of_spinlock_lock(&PRE_IVAR->retain_spinlock));
 	PRE_IVAR->retain_count++;
-	of_spinlock_unlock(&PRE_IVAR->retain_spinlock);
+	assert(of_spinlock_unlock(&PRE_IVAR->retain_spinlock));
 #endif
 
 	return self;
 }
 
@@ -520,13 +523,13 @@
 	if (!of_atomic_dec32(&PRE_IVAR->retain_count))
 		[self dealloc];
 #else
 	int32_t c;
 
-	of_spinlock_lock(&PRE_IVAR->retain_spinlock);
+	assert(of_spinlock_lock(&PRE_IVAR->retain_spinlock));
 	c = --PRE_IVAR->retain_count;
-	of_spinlock_unlock(&PRE_IVAR->retain_spinlock);
+	assert(of_spinlock_unlock(&PRE_IVAR->retain_spinlock));
 
 	if (!c)
 		[self dealloc];
 #endif
 }

Index: src/objc_properties.m
==================================================================
--- src/objc_properties.m
+++ src/objc_properties.m
@@ -8,10 +8,12 @@
  * Q Public License 1.0, which can be found in the file LICENSE included in
  * the packaging of this file.
  */
 
 #include "config.h"
+
+#include <assert.h>
 
 #import <objc/objc.h>
 
 #import "OFExceptions.h"
 
@@ -43,16 +45,16 @@
 	if (atomic) {
 		id *ptr = (id*)((char*)self + offset);
 #ifdef OF_THREADS
 		unsigned hash = SPINLOCK_HASH(ptr);
 
-		of_spinlock_lock(&spinlocks[hash]);
+		assert(of_spinlock_lock(&spinlocks[hash]));
 
 		@try {
 			return [[*ptr retain] autorelease];
 		} @finally {
-			of_spinlock_unlock(&spinlocks[hash]);
+			assert(of_spinlock_unlock(&spinlocks[hash]));
 		}
 #else
 		return [[*ptr retain] autorelease];
 #endif
 	}
@@ -67,11 +69,11 @@
 	if (atomic) {
 		id *ptr = (id*)((char*)self + offset);
 #ifdef OF_THREADS
 		unsigned hash = SPINLOCK_HASH(ptr);
 
-		of_spinlock_lock(&spinlocks[hash]);
+		assert(of_spinlock_lock(&spinlocks[hash]));
 
 		@try {
 #endif
 			id old = *ptr;
 
@@ -92,11 +94,11 @@
 			}
 
 			[old release];
 #ifdef OF_THREADS
 		} @finally {
-			of_spinlock_unlock(&spinlocks[hash]);
+			assert(of_spinlock_unlock(&spinlocks[hash]));
 		}
 #endif
 
 		return;
 	}