diff --git a/liquidprompt b/liquidprompt
index 98592d8..524c6c2 100755
--- a/liquidprompt
+++ b/liquidprompt
@@ -1400,7 +1400,13 @@ _lp_temp_sensors()
 
 _lp_temp_acpi()
 {
-    expr "$(acpi -t)" : '.* \([0-9]*\)\.[0-9]* degrees C'
+    local temperature i
+    temperature=0
+    for i in $(acpi -t | sed 's/.* \([0-9]*\)\.[0-9]* degrees C$/\1/p')
+    do
+        (( $i > $temperature )) && temperature=$i
+    done
+    echo -ne "$temperature"
 }
 
 # Will set _LP_TEMP_FUNCTION so the temperature monitoring feature use an