diff --git a/native/liblinuxbridge/bridge.cpp b/native/liblinuxbridge/bridge.cpp
index 9c6c311..bbe7fda 100644
--- a/native/liblinuxbridge/bridge.cpp
+++ b/native/liblinuxbridge/bridge.cpp
@@ -180,14 +180,13 @@ void event_callback(XPointer p, XRecordInterceptData *hook)
 
     switch (event_type) {
         case KeyRelease:
-            //printf ("%d %d KeyPress: \t%s\t%s\n", key_code, res, XKeysymToString(XkbKeycodeToKeysym(ctrl_disp, key_code, 0, 0)), buffer.data());
-            if (res > 0) {  // Send only printable chars, todo: change
-                keypress_callback(interceptor_instance, buffer.data(), buffer.size());
+            //printf ("%d %d %s\n", key_code, res, buffer.data());
+            if (res > 0 && key_code != 22) {  // Printable character, but not backspace
+                keypress_callback(interceptor_instance, buffer.data(), buffer.size(), 0, key_code);
+            }else{ // Modifier key
+                keypress_callback(interceptor_instance, NULL, 0, 1, key_code);
             }
             break;
-//        case KeyPress:
-//            printf ("%d %d KeyPress: \t%s\t%s\t%d\n", keycode, res, XKeysymToString(XkbKeycodeToKeysym(ctrl_disp, keycode, 0, 0)), buff, buff[0]);
-//            break;
         default:
             break;
     }
diff --git a/native/liblinuxbridge/bridge.h b/native/liblinuxbridge/bridge.h
index ec9a21f..62919cc 100644
--- a/native/liblinuxbridge/bridge.h
+++ b/native/liblinuxbridge/bridge.h
@@ -22,7 +22,7 @@ extern "C" void cleanup();
  * Called when a new keypress is made, the first argument is an char array,
  * while the second is the size of the array.
  */
-typedef void (*KeypressCallback)(void * self, char *buffer, int32_t len);
+typedef void (*KeypressCallback)(void * self, const char *buffer, int32_t len, int32_t is_modifier, int32_t key_code);
 
 extern KeypressCallback keypress_callback;
 extern void * interceptor_instance;
diff --git a/src/keyboard/linux.rs b/src/keyboard/linux.rs
index b131c97..997968c 100644
--- a/src/keyboard/linux.rs
+++ b/src/keyboard/linux.rs
@@ -54,10 +54,10 @@ impl super::KeyboardSender for LinuxKeyboardSender {
 
 // Native bridge code
 
-extern fn keypress_callback(_self: *mut LinuxKeyboardInterceptor, raw_buffer: *const u8, len: i32) {
+extern fn keypress_callback(_self: *mut LinuxKeyboardInterceptor, raw_buffer: *const u8, len: i32,
+                            is_modifier: i32, key_code: i32) {
     unsafe {
-        //if is_modifier == 0 {  // Char event
-        if true {  // Char event
+        if is_modifier == 0 {  // Char event
             // Convert the received buffer to a character
             let buffer = std::slice::from_raw_parts(raw_buffer, len as usize);
             let r = String::from_utf8_lossy(buffer).chars().nth(0);
@@ -67,13 +67,12 @@ extern fn keypress_callback(_self: *mut LinuxKeyboardInterceptor, raw_buffer: *c
                 (*_self).sender.send(KeyEvent::Char(c)).unwrap();
             }
         }else{  // Modifier event
-            let key_code = 3;
             let modifier: Option<KeyModifier> = match key_code {
-                0x37 => Some(META),
-                0x38 => Some(SHIFT),
-                0x3A => Some(ALT),
-                0x3B => Some(CTRL),
-                0x33 => Some(BACKSPACE),
+                133 => Some(META),
+                50 => Some(SHIFT),
+                64 => Some(ALT),
+                37 => Some(CTRL),
+                22 => Some(BACKSPACE),
                 _ => None,
             };
 
@@ -87,7 +86,9 @@ extern fn keypress_callback(_self: *mut LinuxKeyboardInterceptor, raw_buffer: *c
 #[allow(improper_ctypes)]
 #[link(name="linuxbridge", kind="static")]
 extern {
-    fn register_keypress_callback(s: *const LinuxKeyboardInterceptor, cb: extern fn(_self: *mut LinuxKeyboardInterceptor, *const u8, i32));
+    fn register_keypress_callback(s: *const LinuxKeyboardInterceptor,
+                                  cb: extern fn(_self: *mut LinuxKeyboardInterceptor, *const u8,
+                                                i32, i32, i32));
     fn initialize();
     fn eventloop();
     fn cleanup();