Index: src/OFBlock.m
==================================================================
--- src/OFBlock.m
+++ src/OFBlock.m
@@ -133,11 +133,11 @@
 
 		return copy;
 	}
 
 	if (block->isa == (Class)&_NSConcreteMallocBlock)
-		block->reserved++;
+		of_atomic_inc_int(&block->reserved);
 
 	return block;
 }
 
 void
@@ -146,11 +146,11 @@
 	of_block_literal_t *block = (of_block_literal_t*)block_;
 
 	if (block->isa != (Class)&_NSConcreteMallocBlock)
 		return;
 
-	if (--block->reserved == 0) {
+	if (of_atomic_dec_int(&block->reserved) == 0) {
 		if (block->flags & OF_BLOCK_HAS_COPY_DISPOSE)
 			block->descriptor->dispose_helper(block);
 
 		free(block);
 	}