diff --git a/services/auth/Dockerfile b/services/auth/Dockerfile
index 908ddb7..b6ec99d 100644
--- a/services/auth/Dockerfile
+++ b/services/auth/Dockerfile
@@ -2,8 +2,10 @@ FROM node:20-alpine AS build
 WORKDIR /app
 COPY package.json package-lock.json* ./
 # npm ci, not npm install: the image must be the lockfile's content, not
-# whatever resolves the day it is built.
-RUN npm ci
+# whatever resolves the day it is built. --include=dev because this stage
+# needs typescript, and npm omits devDependencies when NODE_ENV=production -
+# which the deployment sets.
+RUN npm ci --include=dev
 COPY . .
 RUN npm run build
 
diff --git a/services/storage/Dockerfile b/services/storage/Dockerfile
index 96ccdf8..6d4862b 100644
--- a/services/storage/Dockerfile
+++ b/services/storage/Dockerfile
@@ -2,8 +2,10 @@ FROM node:20-alpine AS build
 WORKDIR /app
 COPY package.json package-lock.json* ./
 # npm ci, not npm install: the image must be the lockfile's content, not
-# whatever resolves the day it is built.
-RUN npm ci
+# whatever resolves the day it is built. --include=dev because this stage
+# needs typescript, and npm omits devDependencies when NODE_ENV=production -
+# which the deployment sets.
+RUN npm ci --include=dev
 COPY . .
 RUN npm run build
 
diff --git a/services/webmail/Dockerfile b/services/webmail/Dockerfile
index d16f193..952540b 100644
--- a/services/webmail/Dockerfile
+++ b/services/webmail/Dockerfile
@@ -1,7 +1,9 @@
 FROM node:20-alpine AS build
 WORKDIR /app
 COPY package.json package-lock.json* ./
-RUN npm ci
+# --include=dev: the Next build needs devDependencies, and npm omits them
+# when NODE_ENV=production, which the deployment sets.
+RUN npm ci --include=dev
 COPY . .
 RUN npm run build