diff --git a/ct/romm.sh b/ct/romm.sh
index 596964b23..4528dcb57 100644
--- a/ct/romm.sh
+++ b/ct/romm.sh
@@ -218,6 +218,18 @@ DROPEOF
     fi
     msg_ok "Updated ROMM"
 
+    # 5.3.0 refuses to start without filesystem.structure and dropped
+    # roms_folder/firmware_folder. A custom layout cannot be inferred.
+    ROMM_CFG=/var/lib/romm/config/config.yml
+    if [[ -f "$ROMM_CFG" ]] && ! grep -qE '^[[:space:]]*structure:' "$ROMM_CFG"; then
+      if grep -qE '^[[:space:]]*(roms_folder|firmware_folder):' "$ROMM_CFG"; then
+        msg_warn "RomM 5.3.0 removed roms_folder/firmware_folder - replace them with filesystem.structure in ${ROMM_CFG}"
+      else
+        printf '\nfilesystem:\n  structure:\n    default: "roms/{platform}/{game}"\n    firmware: "bios/{platform}"\n' >>"$ROMM_CFG"
+        msg_ok "Added filesystem.structure to ${ROMM_CFG}"
+      fi
+    fi
+
     msg_info "Starting Services"
     systemctl start romm-backend romm-worker romm-scheduler romm-watcher
     msg_ok "Started Services"
diff --git a/install/romm-install.sh b/install/romm-install.sh
index 92b4e0759..d82961ebd 100644
--- a/install/romm-install.sh
+++ b/install/romm-install.sh
@@ -117,9 +117,11 @@ cat <<'EOF' >/var/lib/romm/config/config.yml
 #     gc: ngc
 #     ps1: psx
 
-# The folder name where your roms are located (relative to library path)
-# filesystem:
-#   roms_folder: 'roms'
+# Required since 5.3.0: RomM refuses to start without an explicit structure.
+filesystem:
+  structure:
+    default: "roms/{platform}/{game}"
+    firmware: "bios/{platform}"
 
 # scan:
 #   priority: