diff --git a/.vscode/settings.json b/.vscode/settings.json
index baa76ba..af4ab8e 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,6 +1,7 @@
 {
   "files.associations": {
     "io.h": "c",
-    "delay.h": "c"
+    "delay.h": "c",
+    "interrupt.h": "c"
   }
 }
diff --git a/module02/ex04/main.c b/module02/ex04/main.c
index d059e96..0207079 100644
--- a/module02/ex04/main.c
+++ b/module02/ex04/main.c
@@ -5,6 +5,9 @@
 // mathematics 
 #define DIV_ROUND_CLOSEST(n, d)	((((n) < 0) == ((d) < 0)) ? (((n) + (d)/2)/(d)) : (((n) - (d)/2)/(d))) // https://stackoverflow.com/a/18067292
 
+// text
+#define SWITCH_CASE(ch)			(((ch) >= 'A' && (ch) <= 'Z') || ((ch) >= 'a' && (ch) <= 'z') ? ((ch) ^ (1 << 5)) : (ch))
+
 // stringify
 #define STRINGIFY_HELPER(x)		#x
 #define STRINGIFY(x)			STRINGIFY_HELPER(x)
@@ -115,9 +118,6 @@
 #define INTERRUPT_ENABLE_CHANNEL_A		(1 << OCIE1A)
 #define INTERRUPT_DISABLE_CHANNEL_A		(0 << OCIE1A)
 
-// text
-#define SWITCH_CASE(ch) (((ch) >= 'A' && (ch) <= 'Z') || ((ch) >= 'a' && (ch) <= 'z') ? ((ch) ^ (1 << 5)) : (ch))
-
 // END MACROS
 
 void uart_init() {