diff --git a/rechnung.sh b/rechnung.sh
index 6351d2f..e9fc0d4 100755
--- a/rechnung.sh
+++ b/rechnung.sh
@@ -21,7 +21,8 @@ DATE_BIN=$(which date 2>/dev/null || echo "date")
 TPUT_BIN=$(which tput 2>/dev/null || echo "tput")
 PDFLATEX_BIN=$(which pdflatex 2>/dev/null || echo "pdflatex")
 RUBBER_BIN=$(which rubber 2>/dev/null || echo "rubber")
-EXECUTABLES_TO_CHECK="$BC_BIN $TR_BIN $SED_BIN $CUT_BIN $TPUT_BIN $DATE_BIN $PDFLATEX_BIN $RUBBER_BIN"
+# Nicht auf rubber prüfen; Programm ist optional
+EXECUTABLES_TO_CHECK="$BC_BIN $TR_BIN $SED_BIN $CUT_BIN $TPUT_BIN $DATE_BIN $PDFLATEX_BIN"
 
 GENPDF=""
 if [ -x "$RUBBER_BIN" ]; then