diff --git a/i3/i3blocks/blocks/brightness b/i3/i3blocks/blocks/brightness
index 228b517..47efe27 100755
--- a/i3/i3blocks/blocks/brightness
+++ b/i3/i3blocks/blocks/brightness
@@ -8,8 +8,14 @@ get_brighntess() {
 }
 
 set_brightness() {
-    xrandr --output $output --brightness $(echo $1 | awk '{printf "%0.2f", $1/100}' )
     brightness=$1
+    if [ "$brightness" -gt 100 ]; then
+        brightness=100
+    fi
+    if [ "$brightness" -lt 0 ]; then
+        brightness=0
+    fi
+    xrandr --output $output --brightness $(echo $brightness | awk '{printf "%0.2f", $1/100}' )
 }
 
 get_brighntess