diff --git a/matrix.py b/matrix.py
index b63e5d0..42252ba 100644
--- a/matrix.py
+++ b/matrix.py
@@ -371,7 +371,7 @@ class Matrix64Display(SampleBase):
         graphics.DrawLine(canvas, 28, 0, 28, 25, line_color)
 
         if self.hdd_temps and len(self.hdd_temps) > 1:
-            temps = [str(int(t[0])) for t in self.hdd_temps[1:] if t]
+            temps = [str(int(t[0])) for t in self.hdd_temps[1:] if t and t[0] is not None]
             if len(temps) >= 2:
                 graphics.DrawText(canvas, data_font, 34, 8, hdd_color, " ".join(temps[:2]))
             if len(temps) >= 4:
@@ -411,7 +411,7 @@ class Matrix64Display(SampleBase):
         graphics.DrawLine(canvas, 0, 10, 63, 10, line_color)
         
         if self.hdd_temps and len(self.hdd_temps) > 1:
-            temps = [(i+1, int(t[0])) for i, t in enumerate(self.hdd_temps[1:7]) if t]
+            temps = [(i+1, int(t[0])) for i, t in enumerate(self.hdd_temps[1:7]) if t and t[0] is not None]
             
             y = 22
             for idx, (num, temp_val) in enumerate(temps[:3]):