diff --git a/src/lib.rs b/src/lib.rs
index 8f124bd..7bbc928 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -741,7 +741,7 @@ impl Device {
         let mut bits64: u64 = 0;
         let mut vec = Vec::with_capacity(256);
 
-        do_ioctl!(eviocgbit(*fd, 0, 4, &mut bits as *mut _ as *mut u8));
+        do_ioctl!(eviocgbit(*fd, 0, 4, &mut bits as *mut u32 as *mut u8));
         dev.ty = Types::from_bits(bits).expect("evdev: unexpected type bits! report a bug");
 
         let dev_len = do_ioctl!(eviocgname(*fd, vec.as_mut_ptr(), 255));
@@ -768,7 +768,7 @@ impl Device {
              ((driver_version >> 8) & 0xff) as u8,
               (driver_version & 0xff) as u8);
 
-        do_ioctl!(eviocgprop(*fd, &mut bits as *mut _ as *mut u8, 0x1f)); // FIXME: handle old kernel
+        do_ioctl!(eviocgprop(*fd, &mut bits as *mut u32 as *mut u8, 0x1f)); // FIXME: handle old kernel
         dev.props = Props::from_bits(bits).expect("evdev: unexpected prop bits! report a bug");
 
         if dev.ty.contains(KEY) {
@@ -776,36 +776,36 @@ impl Device {
         }
 
         if dev.ty.contains(RELATIVE) {
-            do_ioctl!(eviocgbit(*fd, RELATIVE.number(), 0xf, &mut bits as *mut _ as *mut u8));
+            do_ioctl!(eviocgbit(*fd, RELATIVE.number(), 0xf, &mut bits as *mut u32 as *mut u8));
             dev.rel = RelativeAxis::from_bits(bits).expect("evdev: unexpected rel bits! report a bug");
         }
 
         if dev.ty.contains(ABSOLUTE) {
-            do_ioctl!(eviocgbit(*fd, ABSOLUTE.number(), 0x3f, &mut bits64 as *mut _ as *mut u8));
+            do_ioctl!(eviocgbit(*fd, ABSOLUTE.number(), 0x3f, &mut bits64 as *mut u64 as *mut u8));
             println!("abs bits: {:b}", bits64);
             dev.abs = AbsoluteAxis::from_bits(bits64).expect("evdev: unexpected abs bits! report a bug");
             dev.state.abs_vals = vec![ioctl::input_absinfo::default(); 0x3f];
         }
 
         if dev.ty.contains(SWITCH) {
-            do_ioctl!(eviocgbit(*fd, SWITCH.number(), 0xf, &mut bits as *mut _ as *mut u8));
+            do_ioctl!(eviocgbit(*fd, SWITCH.number(), 0xf, &mut bits as *mut u32 as *mut u8));
             dev.switch = Switch::from_bits(bits).expect("evdev: unexpected switch bits! report a bug");
         }
 
         if dev.ty.contains(LED) {
-            do_ioctl!(eviocgbit(*fd, LED.number(), 0xf, &mut bits as *mut _ as *mut u8));
+            do_ioctl!(eviocgbit(*fd, LED.number(), 0xf, &mut bits as *mut u32 as *mut u8));
             dev.led = Led::from_bits(bits).expect("evdev: unexpected led bits! report a bug");
         }
 
         if dev.ty.contains(MISC) {
-            do_ioctl!(eviocgbit(*fd, MISC.number(), 0x7, &mut bits as *mut _ as *mut u8));
+            do_ioctl!(eviocgbit(*fd, MISC.number(), 0x7, &mut bits as *mut u32 as *mut u8));
             dev.misc = Misc::from_bits(bits).expect("evdev: unexpected misc bits! report a bug");
         }
 
-        //do_ioctl!(eviocgbit(*fd, ffs(FORCEFEEDBACK.bits()), 0x7f, &mut bits as *mut _ as *mut u8));
+        //do_ioctl!(eviocgbit(*fd, ffs(FORCEFEEDBACK.bits()), 0x7f, &mut bits as *mut u32 as *mut u8));
 
         if dev.ty.contains(SOUND) {
-            do_ioctl!(eviocgbit(*fd, SOUND.number(), 0x7, &mut bits as *mut _ as *mut u8));
+            do_ioctl!(eviocgbit(*fd, SOUND.number(), 0x7, &mut bits as *mut u32 as *mut u8));
             dev.snd = Sound::from_bits(bits).expect("evdev: unexpected sound bits! report a bug");
         }
 
@@ -820,7 +820,7 @@ impl Device {
     /// If there is an error at any point, the state will not be synchronized completely.
     pub fn sync_state(&mut self) -> Result<(), Error> {
         if self.ty.contains(KEY) {
-            do_ioctl!(eviocgkey(self.fd, self.state.key_vals.as_mut_slice().as_mut_ptr() as *mut _ as *mut u8, self.state.key_vals.len()));
+            do_ioctl!(eviocgkey(self.fd, self.state.key_vals.as_mut_slice().as_mut_ptr() as *mut u32 as *mut u8, self.state.key_vals.len()));
         }
         if self.ty.contains(ABSOLUTE) {
             for idx in (0..0x28) {
@@ -832,10 +832,10 @@ impl Device {
             }
         }
         if self.ty.contains(SWITCH) {
-            do_ioctl!(eviocgsw(self.fd, &mut self.state.switch_vals.as_mut_slice().as_mut_ptr() as *mut _ as *mut u8, self.state.switch_vals.len()));
+            do_ioctl!(eviocgsw(self.fd, self.state.switch_vals.as_mut_slice().as_mut_ptr() as *mut u32 as *mut u8, self.state.switch_vals.len()));
         }
         if self.ty.contains(LED) {
-            do_ioctl!(eviocgled(self.fd, &mut self.state.led_vals.as_mut_slice().as_mut_ptr() as *mut _ as *mut u8, self.state.led_vals.len()));
+            do_ioctl!(eviocgled(self.fd, self.state.led_vals.as_mut_slice().as_mut_ptr() as *mut u32 as *mut u8, self.state.led_vals.len()));
         }
 
         Ok(())