diff --git a/utils/raspberrypi/ctt/ctt.py b/utils/raspberrypi/ctt/ctt.py
index d7e38c31986d..30d35ae4e3d4 100755
--- a/utils/raspberrypi/ctt/ctt.py
+++ b/utils/raspberrypi/ctt/ctt.py
@@ -42,8 +42,8 @@ def get_col_lux(string):
     """
     Extract colour and lux values from filename
     """
-    col = re.search('([0-9]+)[kK](\.(jpg|jpeg|brcm|dng)|_.*\.(jpg|jpeg|brcm|dng))$', string)
-    lux = re.search('([0-9]+)[lL](\.(jpg|jpeg|brcm|dng)|_.*\.(jpg|jpeg|brcm|dng))$', string)
+    col = re.search(r'([0-9]+)[kK](\.(jpg|jpeg|brcm|dng)|_.*\.(jpg|jpeg|brcm|dng))$', string)
+    lux = re.search(r'([0-9]+)[lL](\.(jpg|jpeg|brcm|dng)|_.*\.(jpg|jpeg|brcm|dng))$', string)
     try:
         col = col.group(1)
     except AttributeError:
diff --git a/utils/raspberrypi/ctt/ctt_awb.py b/utils/raspberrypi/ctt/ctt_awb.py
index 7055b8639178..3c8cd9027a1a 100644
--- a/utils/raspberrypi/ctt/ctt_awb.py
+++ b/utils/raspberrypi/ctt/ctt_awb.py
@@ -257,8 +257,8 @@ def awb(Cam, cal_cr_list, cal_cb_list, plot):
         plt.scatter(rbs_hat[0], rbs_hat[1], color='red')
         for i, ct in enumerate(rbs_hat[2]):
             plt.annotate(str(ct), (rbs_hat[0][i], rbs_hat[1][i]))
-        plt.xlabel('$\hat{r}$')
-        plt.ylabel('$\hat{b}$')
+        plt.xlabel('$\\hat{r}$')
+        plt.ylabel('$\\hat{b}$')
         """
         optional set axes equal to shortest distance so line really does
         looks perpendicular and everybody is happy