diff --git a/rpi/first-boot-wizard.sh b/rpi/first-boot-wizard.sh
index 0038c6c..bb806a8 100755
--- a/rpi/first-boot-wizard.sh
+++ b/rpi/first-boot-wizard.sh
@@ -76,11 +76,20 @@ gum style --foreground 245 "Current: $CURRENT_SIZE"
 echo ""
 
 if gum confirm "Expand filesystem to fill SD card?" --default=true; then
+  # Get the disk device (strip partition number) and partition number
+  DISK_DEV=$(echo "$ROOT_DEV" | sed 's/p\?[0-9]*$//')
+  PART_NUM=$(echo "$ROOT_DEV" | grep -o '[0-9]*$')
+
+  # Step 1: Grow partition to fill disk
+  gum spin --spinner dot --title "Expanding partition..." -- sudo growpart "$DISK_DEV" "$PART_NUM" 2>/dev/null || true
+
+  # Step 2: Resize filesystem to fill partition
   gum spin --spinner dot --title "Expanding filesystem..." -- sudo resize2fs "$ROOT_DEV" 2>/dev/null
+
   NEW_SIZE=$(df -h / | awk 'NR==2 {print $2}')
   gum style --foreground 82 "✓ Expanded to: $NEW_SIZE"
 else
-  gum style --foreground 214 "→ Skipped (you can run 'sudo resize2fs $ROOT_DEV' later)"
+  gum style --foreground 214 "→ Skipped (run 'sudo growpart /dev/sdX 2 && sudo resize2fs /dev/sdX2' later)"
 fi
 sleep 1