diff --git a/src/add-ons/input_server/devices/keyboard/KeyboardInputDevice.cpp b/src/add-ons/input_server/devices/keyboard/KeyboardInputDevice.cpp
index 5b7460792e..ef963d2621 100644
--- a/src/add-ons/input_server/devices/keyboard/KeyboardInputDevice.cpp
+++ b/src/add-ons/input_server/devices/keyboard/KeyboardInputDevice.cpp
@@ -282,7 +282,7 @@ KeyboardDevice::_ControlThread()
 	memset(states, 0, sizeof(states));
 
 	while (fActive) {
-		if (ioctl(fFD, KB_READ, &keyInfo) != B_OK) {
+		if (ioctl(fFD, KB_READ, &keyInfo, sizeof(keyInfo)) != B_OK) {
 			_ControlThreadCleanup();
 			// TOAST!
 			return 0;
diff --git a/src/add-ons/input_server/devices/tablet/TabletInputDevice.cpp b/src/add-ons/input_server/devices/tablet/TabletInputDevice.cpp
index 00eecd2ed2..7ce8e0645c 100644
--- a/src/add-ons/input_server/devices/tablet/TabletInputDevice.cpp
+++ b/src/add-ons/input_server/devices/tablet/TabletInputDevice.cpp
@@ -322,7 +322,8 @@ TabletInputDevice::DeviceWatcher(void *arg)
 	BMessage *message;
 	while (dev->active) {
 		memset(&movements, 0, sizeof(movements));
-		if (ioctl(dev->fd, MS_READ, &movements) != B_OK) {
+		if (ioctl(dev->fd, MS_READ, &movements, 
+			sizeof(movements)) != B_OK) {
 			snooze(10000); // this is a realtime thread, and something is wrong...
 			continue;
 		}