diff --git a/src/console.asm b/src/console.asm
index 30da9c3..8347f58 100644
--- a/src/console.asm
+++ b/src/console.asm
@@ -1,9 +1,5 @@
-extern	EOS
-extern	NL
-extern	NR_write
-extern	FD_stdin
-extern	FD_stdout
-extern	FD_stderr
+%include "src/constants.asm"
+
 extern	strlen
 extern	itoa
 
diff --git a/src/core.asm b/src/core.asm
index 9bc5b8b..f0501cf 100644
--- a/src/core.asm
+++ b/src/core.asm
@@ -1,4 +1,4 @@
-extern	NR_exit
+%include "src/constants.asm"
 extern	strclr
 
 section	.text
diff --git a/src/file.asm b/src/file.asm
index 4293d28..b8bec41 100644
--- a/src/file.asm
+++ b/src/file.asm
@@ -1,9 +1,4 @@
-extern	FD_stderr
-extern	NR_read
-extern	NR_write
-extern	NR_open
-extern	NR_close
-
+%include "src/constants.asm"
 extern	strlen
 
 section .rodata
diff --git a/src/tests.asm b/src/tests.asm
index 4c14a62..04cb23b 100644
--- a/src/tests.asm
+++ b/src/tests.asm
@@ -1,6 +1,5 @@
-;constants.asm
-extern	EOS
-extern	NL
+%include "src/constants.asm"
+
 ;core.asm
 extern	min
 extern	minu