diff --git a/scripts/Check-System b/scripts/Check-System
index d9d84638e..9cb707e44 100755
--- a/scripts/Check-System
+++ b/scripts/Check-System
@@ -74,7 +74,7 @@ case $BASH_VERSION in
 	echo "You need to update 'bash' to at least version 2.05b."
 	found_error=1
 esac
-	
+
 
 x="`mktemp -p /tmp 2> /dev/null`"
 if [ -z "$x" -o ! -f "$x" ] ; then
@@ -87,6 +87,15 @@ else
 	rm -f "$x"
 fi
 
+if [ -z "`type -p sed`" ] || ! sed -i s/a/b/ < /dev/null 2> /dev/null
+then
+	echo
+	echo "Paranoia Check: Program 'sed' not found or too old!"
+	echo "You need a 'sed' installed which does know about the -i option"
+	echo "(GNU/sed since 2001-09-25). Install the latest sed version."
+	found_error=1
+fi
+
 if [ $found_error -ne 0 ] ; then
 	echo
 	echo "Paranoia Check found errors -> not doing anything."