diff --git a/xo-install.sh b/xo-install.sh
index cf8c9d5..cb2c2bf 100755
--- a/xo-install.sh
+++ b/xo-install.sh
@@ -1263,7 +1263,7 @@ function CheckOS {
         exit 1
     fi
 
-    if [[ "$OSNAME" == "CentOS" ]] && [[ "$OSVERSION" =~ ^(8|9)$ ]]; then
+    if [[ "$OSNAME" == "CentOS" ]] && [[ ! "$OSVERSION" =~ ^(8|9)$ ]]; then
         printfail "Only CentOS 8/9 supported"
         exit 1
     fi