diff --git a/libisoburn/trunk/releng/auto_isocontent b/libisoburn/trunk/releng/auto_isocontent
index 8935a61b..e24a8fab 100755
--- a/libisoburn/trunk/releng/auto_isocontent
+++ b/libisoburn/trunk/releng/auto_isocontent
@@ -83,7 +83,8 @@ is_valid_iso9660() {
    failure=1
    printf "\nFAIL : ${SELF} : Not found: ${ISOfile}\n"
  fi
- if file ${ISOfile} | grep -P "ISO\s+9660\s+CD-ROM\s+filesystem\s+data" >/dev/null 2>&1; then
+ file ${ISOfile}
+ if file ${ISOfile} | grep  "ISO *9660" >/dev/null 2>&1; then
    printf "\n${SELF}: Resulting ${ISOfile} OK. Looks like ISO 9660 filesystem.\n"
  else
    failure=1