diff --git a/imuread.h b/imuread.h
index 6bcae6f..5e09d77 100644
--- a/imuread.h
+++ b/imuread.h
@@ -15,8 +15,8 @@
 #if defined(LINUX)
   #include <termios.h>
   #include <unistd.h>
-  #include <GL/gl.h>
-  #include <GL/glu.h>
+  #include <GL/gl.h>  // sudo apt install mesa-common-dev
+  #include <GL/glu.h> // sudo apt install libglu1-mesa-dev freeglut3-dev
 #elif defined(WINDOWS)
   #include <windows.h>
   #include <GL/gl.h>
diff --git a/rawdata.c b/rawdata.c
index e230036..c77fec7 100644
--- a/rawdata.c
+++ b/rawdata.c
@@ -186,10 +186,10 @@ void raw_data(const int16_t *data)
 	z = (float)data[2] * G_PER_COUNT;
 	accel.GpFast[0] = x;
 	accel.GpFast[1] = y;
-	accel.GpFast[2] = y;
+	accel.GpFast[2] = z;
 	accel.Gp[0] += x;
 	accel.Gp[1] += y;
-	accel.Gp[2] += y;
+	accel.Gp[2] += z;
 
 	x = (float)data[3] * DEG_PER_SEC_PER_COUNT;
 	y = (float)data[4] * DEG_PER_SEC_PER_COUNT;