diff --git a/x86_64/airootfs/usr/local/bin/install-stormux b/x86_64/airootfs/usr/local/bin/install-stormux
index be18ff7..90edcf5 100755
--- a/x86_64/airootfs/usr/local/bin/install-stormux
+++ b/x86_64/airootfs/usr/local/bin/install-stormux
@@ -1461,10 +1461,10 @@ install_base_system() {
 
     # Generate or preserve fstab
     if [[ "$useExistingMount" == true ]]; then
-        if [[ -s "$mountPoint/etc/fstab" ]]; then
+        if grep -Eq '^[[:space:]]*[^#[:space:]]' "$mountPoint/etc/fstab" 2>/dev/null; then
             log_info "Manual mount mode: preserving existing /etc/fstab"
         else
-            log_warning "Manual mount mode: /etc/fstab not found, generating one"
+            log_warning "Manual mount mode: /etc/fstab has no filesystem entries, generating one"
             genfstab -U "$mountPoint" > "$mountPoint/etc/fstab"
         fi
     else