diff --git a/F250/createImages b/F250/createImages
index 20f26b288955bbb813cd2581b451e1a8e258bfd7..2f11af33604f53bdcb2f237c89dea9f32f1aff6e 100755
--- a/F250/createImages
+++ b/F250/createImages
@@ -49,6 +49,7 @@ digitFile[7]='digit-7.png'
 digitFile[8]='digit-8.png'
 digitFile[9]='digit-9.png'
 digitFile[10]='minus.png'
+digitFile[11]=$emptyCanvas
 
 dotFile='dot.png'
 minusFile='minus.png' 
@@ -65,6 +66,7 @@ NUM2CHAR[7]='7'
 NUM2CHAR[8]='8'
 NUM2CHAR[9]='9'
 NUM2CHAR[10]='-'
+NUM2CHAR[11]='_'
 
 digitPos[1]='+197+198'
 digitPos[2]='+238+198'
@@ -84,7 +86,7 @@ value=""
 DPR=$((RANDOM % $NUMBER_OF_DIGITS + 1)) # random dot position (1..$NUMBER_OF_DIGITS)
 for (( i=1; i<=$MAX_DIGITS; i++ )); do
   if (( $i <= $NUMBER_OF_DIGITS )); then
-    R=$((RANDOM % 11)) # random digit number (0..10 = '0'..'-')
+    R=$((RANDOM % 12)) # random digit number (0..11 = '0'..'_')
     eval DIGIT$i=${digitFile[R]}
     value+="${NUM2CHAR[R]}"
     if [ $DPR == $i ]; then