diff --git a/Dockerfile b/Dockerfile
index 1399ef3..7dc4824 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,6 +10,14 @@
 # will be added before anyone tries to build this image.
 FROM eclipse-temurin:21-jdk-alpine AS build
 
+# Node + npm are required for the :web Gradle subproject's npm-based
+# Vite build. The bootJar wires the SPA bundle into Spring Boot's
+# classpath:/static/ via processResources, so a clean container build
+# of `:distribution:bootJar` transitively runs `:web:npmInstall` and
+# `:web:npmBuild` and needs npm on PATH. Apk's nodejs/npm packages
+# track v22.x on Alpine 3.21, which Vite 5 + React 18 are happy with.
+RUN apk add --no-cache nodejs npm
+
 WORKDIR /workspace
 COPY . .