diff --git a/src/block.c b/src/block.c
index 60c8d15..1209898 100644
--- a/src/block.c
+++ b/src/block.c
@@ -9,6 +9,7 @@
 #include "align.h"
 #include "chunk.h"
 #include "chunk_manager.h"
+#include "malloc.h"
 
 int add_new_block(chunk_t* chunk, size_t size, void *prev, bool is_used)
 {
@@ -19,7 +20,7 @@ int add_new_block(chunk_t* chunk, size_t size, void *prev, bool is_used)
 	// TODO check with getrlimit()
 
 	new_block = mmap(NULL, size + ALIGN_MARGING + HEADER_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-#ifndef DEBUG
+#ifdef DEBUG
 	if (new_block == NULL)
 		write(2, "mmap failed\n", 12);
 #endif
diff --git a/src/chunk_manager.c b/src/chunk_manager.c
index 192769c..054319d 100644
--- a/src/chunk_manager.c
+++ b/src/chunk_manager.c
@@ -3,12 +3,13 @@
 #include "raw_chunk_manager.h"
 #include "print.h"
 #include "block.h"
+#include "malloc.h"
 
 #include <unistd.h>
 
 void chunk_merge(chunk_t *first, chunk_t *second)
 {
-#ifndef DEBUG
+#ifdef DEBUG
     if (first->block_id != second->block_id)
         write(2, "Attempt merge two chunk on different block\n", 43);
 #endif        
@@ -22,7 +23,7 @@ int chunk_split(chunk_t *chunk, size_t new_size)
 {
     chunk_t new_chunk;
 
-#ifndef DEBUG
+#ifdef DEBUG
 	if (chunk->size + 1 < new_size + HEADER_SIZE + get_align_increment(chunk->current + HEADER_SIZE))
         write(2, "chunk too small to be splitted\n", 31);
 #endif
diff --git a/src/free.c b/src/free.c
index 1b22556..472a4ff 100644
--- a/src/free.c
+++ b/src/free.c
@@ -57,7 +57,7 @@ void ft_free(void *ptr)
 
 	for (i = TINY; i <= LARGE + 1; i++)
 	{
-#ifndef DEBUG
+#ifdef DEBUG
 		if (i > LARGE)
 			write(2, "chunk not found\n", 16);
 #endif
@@ -72,7 +72,7 @@ void ft_free(void *ptr)
 
 	chunk_read(raw_chunk, &chunk);
 
-#ifndef DEBUG
+#ifdef DEBUG
 	if (chunk.is_used == false)
 		write(2, "double free\n", 12);
 #endif