diff --git a/src/main.c b/src/main.c
index ba406fd..aafc928 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,6 +14,7 @@
 #include <termios.h>
 #include <errno.h>
 #include <locale.h>
+#include <stdlib.h>
 
 const int digit_bitmaps[10][5][3] = {
         {{1,1,1},{1,0,1},{1,0,1},{1,0,1},{1,1,1}}, // 0
@@ -138,7 +139,7 @@ void read_can(Tel *t, int soc) {
 
                 case 0x382:
                         if (frame.can_dlc >= 2) {
-                                t->rpm.data = frame.data[0] | (frame.data[1] << 8);
+                                t->rpm.data = abs((int16_t)(frame.data[0] | (frame.data[1] << 8)));
                         }
                         break;
                 default: