diff --git a/src/core/heap.c b/src/core/heap.c
index 3476f4d2..05fbb6ba 100644
--- a/src/core/heap.c
+++ b/src/core/heap.c
@@ -3,8 +3,6 @@
 #include "memsizes.h"
 #include "heap.h"
 
-#define ASSERT(...)
-
 struct heap_block {
 	size_t size;
 	char data[0];
@@ -102,7 +100,7 @@ void * emalloc ( size_t size, unsigned int align ) {
 	physaddr_t addr;
 	struct heap_block *block;
 	
-	ASSERT ( ! ( align & ( align - 1 ) ) );
+	ASSERT ( ( align & ( align - 1 ) ) == 0 );
 	
 	addr = ( ( ( heap_ptr - size ) & ~( align - 1 ) )
 		 - sizeof ( struct heap_block ) );
@@ -132,7 +130,7 @@ void * emalloc_all ( size_t *size ) {
 void efree ( void *ptr ) {
 	struct heap_block *block;
 
-	ASSERT ( ptr == ( heap_ptr + sizeof ( size_t ) ) );
+	ASSERT ( ptr == phys_to_virt ( heap_ptr + sizeof ( size_t ) ) );
 	
 	block = ( struct heap_block * )
 		( ptr - offsetof ( struct heap_block, data ) );
diff --git a/src/include/compiler.h b/src/include/compiler.h
index 7d7c5960..4912b424 100644
--- a/src/include/compiler.h
+++ b/src/include/compiler.h
@@ -67,6 +67,23 @@ __asm__ ( ".equ\tDEBUG_LEVEL, " DEBUG_SYMBOL_STR );
 #define DBG2 DBG_PRINT
 #endif
 
+/*
+ * ASSERT() macros
+ *
+ */
+#define ASSERT(x)
+
+#if DEBUG_SYMBOL >= 1
+#undef ASSERT
+#define ASSERT(x) 							      \
+	do { 								      \
+		if ( ! (x) ) { 						      \
+			DBG ( "ASSERT(%s) failed at %s line %d [%s]\n", #x,   \
+			      __FILE__, __LINE__, __FUNCTION__ );	      \
+		} 							      \
+	} while (0)
+#endif
+
 #define PACKED __attribute__((packed))
 #define __unused __attribute__((unused))
 #define __used __attribute__((used))