diff --git a/UPGRADE.md b/UPGRADE.md
index 47b58bc..378aa7e 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -12,6 +12,7 @@
 
 ## Upgrade from v5.0.0 to v5.1.0
 
+- cache warmup is now run as an init container instead of a `postStart` lifecycle hook ([#73](https://github.com/shopsys/deployment/pull/73))
 - cron pod is now always deleted gracefully ([#72](https://github.com/shopsys/deployment/pull/72))
 - health check for webserver now uses PHP-FPM `ping` endpoint instead of nginx `stub_status` ([#71](https://github.com/shopsys/deployment/pull/71))
 - update the `/health` location block in `project-nginx.conf` in your project's `app/orchestration/kubernetes/configmap/nginx.yaml` file to pass the request to PHP-FPM:
diff --git a/deploy/parts/environment-variables.sh b/deploy/parts/environment-variables.sh
index e9b3792..6c28277 100644
--- a/deploy/parts/environment-variables.sh
+++ b/deploy/parts/environment-variables.sh
@@ -39,6 +39,14 @@ for key in "${!ENVIRONMENT_VARIABLES[@]}"; do
           }
         " "${CONFIGURATION_TARGET_PATH}/deployments/webserver-php-fpm.yaml"
 
+        # Webserver PHP-FPM warmup container
+        yq e -i "
+          .spec.template.spec.initContainers[1].env[${ITERATOR}] = {
+            \"name\": \"${key}\",
+            \"value\": \"${ENVIRONMENT_VARIABLES[$key]}\"
+          }
+        " "${CONFIGURATION_TARGET_PATH}/deployments/webserver-php-fpm.yaml"
+
         # Cron deployment
         yq e -i "
           .spec.template.spec.containers[0].env[${ITERATOR}] = {
@@ -145,4 +153,4 @@ yq e -i "
 unset YQ_KEY
 unset YQ_VALUE
 
-echo -e "[${GREEN}OK${NO_COLOR}]"
\ No newline at end of file
+echo -e "[${GREEN}OK${NO_COLOR}]"
diff --git a/kubernetes/deployments/webserver-php-fpm.yaml b/kubernetes/deployments/webserver-php-fpm.yaml
index c8c5cc0..0d50252 100644
--- a/kubernetes/deployments/webserver-php-fpm.yaml
+++ b/kubernetes/deployments/webserver-php-fpm.yaml
@@ -83,15 +83,21 @@ spec:
                         -   name: domains-urls
                             mountPath: /var/www/html/{{DOMAINS_URLS_FILEPATH}}
                             subPath: "{{DOMAINS_URLS_FILENAME}}"
+                -   name: warmup
+                    image: "{{TAG}}"
+                    command: ["/var/www/html/phing", "-S", "warmup"]
+                    volumeMounts:
+                        -   name: source-codes
+                            mountPath: /var/www/html
+                        -   name: domains-urls
+                            mountPath: /var/www/html/{{DOMAINS_URLS_FILEPATH}}
+                            subPath: "{{DOMAINS_URLS_FILENAME}}"
             containers:
                 -   image: "{{TAG}}"
                     name: php-fpm
                     imagePullPolicy: IfNotPresent
                     workingDir: /var/www/html
                     lifecycle:
-                        postStart:
-                            exec:
-                                command: ["/var/www/html/phing", "-S", "warmup"]
                         preStop:
                             exec:
                                 command: ["/bin/sh","-lc","sleep 10; kill -QUIT 1 || true"]
diff --git a/tests/scenarios/basic-production/expected/webserver.yaml b/tests/scenarios/basic-production/expected/webserver.yaml
index 4829d3f..9ea6305 100644
--- a/tests/scenarios/basic-production/expected/webserver.yaml
+++ b/tests/scenarios/basic-production/expected/webserver.yaml
@@ -741,12 +741,6 @@ spec:
         image: v1.0.0
         imagePullPolicy: IfNotPresent
         lifecycle:
-          postStart:
-            exec:
-              command:
-              - /var/www/html/phing
-              - -S
-              - warmup
           preStop:
             exec:
               command:
@@ -854,6 +848,53 @@ spec:
         - mountPath: /var/www/html/config/domains_urls.yaml
           name: domains-urls
           subPath: domains_urls.yaml
+      - command:
+        - /var/www/html/phing
+        - -S
+        - warmup
+        env:
+        - name: ELASTICSEARCH_HOST
+          value: http://elasticsearch:9200
+        - name: TRUSTED_PROXY
+          value: 10.0.0.0/8
+        - name: DATABASE_NAME
+          value: myproject-production
+        - name: S3_ENDPOINT
+          value: https://s3.example.com
+        - name: MAILER_FORCE_WHITELIST
+          value: "false"
+        - name: DATABASE_USER
+          value: myproject-production
+        - name: DATABASE_PORT
+          value: "5432"
+        - name: MESSENGER_TRANSPORT_DSN
+          value: amqp://guest:guest@rabbitmq:5672/%2f/messages
+        - name: REDIS_PREFIX
+          value: myproject-production
+        - name: DATABASE_PASSWORD
+          value: test-db-password
+        - name: DATABASE_HOST
+          value: 10.0.0.100
+        - name: ELASTIC_SEARCH_INDEX_PREFIX
+          value: myproject-production
+        - name: S3_SECRET
+          value: test-s3-secret
+        - name: MAILER_DSN
+          value: smtp://mailhog:1025
+        - name: S3_BUCKET_NAME
+          value: myproject-production
+        - name: S3_ACCESS_KEY
+          value: myproject-production
+        - name: APP_SECRET
+          value: test-app-secret-key
+        image: v1.0.0
+        name: warmup
+        volumeMounts:
+        - mountPath: /var/www/html
+          name: source-codes
+        - mountPath: /var/www/html/config/domains_urls.yaml
+          name: domains-urls
+          subPath: domains_urls.yaml
       terminationGracePeriodSeconds: 120
       volumes:
       - emptyDir: {}
diff --git a/tests/scenarios/development-single-domain/expected/webserver.yaml b/tests/scenarios/development-single-domain/expected/webserver.yaml
index 071b317..86d00b3 100644
--- a/tests/scenarios/development-single-domain/expected/webserver.yaml
+++ b/tests/scenarios/development-single-domain/expected/webserver.yaml
@@ -735,12 +735,6 @@ spec:
         image: dev-latest
         imagePullPolicy: IfNotPresent
         lifecycle:
-          postStart:
-            exec:
-              command:
-              - /var/www/html/phing
-              - -S
-              - warmup
           preStop:
             exec:
               command:
@@ -848,6 +842,53 @@ spec:
         - mountPath: /var/www/html/config/domains_urls.yaml
           name: domains-urls
           subPath: domains_urls.yaml
+      - command:
+        - /var/www/html/phing
+        - -S
+        - warmup
+        env:
+        - name: ELASTICSEARCH_HOST
+          value: http://elasticsearch:9200
+        - name: TRUSTED_PROXY
+          value: 10.0.0.0/8
+        - name: DATABASE_NAME
+          value: myproject-dev
+        - name: S3_ENDPOINT
+          value: https://s3.example.com
+        - name: MAILER_FORCE_WHITELIST
+          value: "true"
+        - name: DATABASE_USER
+          value: myproject-dev
+        - name: DATABASE_PORT
+          value: "5432"
+        - name: MESSENGER_TRANSPORT_DSN
+          value: amqp://guest:guest@rabbitmq:5672/%2f/messages
+        - name: REDIS_PREFIX
+          value: myproject-dev
+        - name: DATABASE_PASSWORD
+          value: test-db-password
+        - name: DATABASE_HOST
+          value: 10.0.0.100
+        - name: ELASTIC_SEARCH_INDEX_PREFIX
+          value: myproject-dev
+        - name: S3_SECRET
+          value: test-s3-secret
+        - name: MAILER_DSN
+          value: smtp://mailhog:1025
+        - name: S3_BUCKET_NAME
+          value: myproject-dev
+        - name: S3_ACCESS_KEY
+          value: myproject-dev
+        - name: APP_SECRET
+          value: test-app-secret-key
+        image: dev-latest
+        name: warmup
+        volumeMounts:
+        - mountPath: /var/www/html
+          name: source-codes
+        - mountPath: /var/www/html/config/domains_urls.yaml
+          name: domains-urls
+          subPath: domains_urls.yaml
       terminationGracePeriodSeconds: 120
       volumes:
       - emptyDir: {}
diff --git a/tests/scenarios/escaping-env/expected/webserver.yaml b/tests/scenarios/escaping-env/expected/webserver.yaml
index fe02564..97d9950 100644
--- a/tests/scenarios/escaping-env/expected/webserver.yaml
+++ b/tests/scenarios/escaping-env/expected/webserver.yaml
@@ -748,12 +748,6 @@ spec:
         image: v1.0.0
         imagePullPolicy: IfNotPresent
         lifecycle:
-          postStart:
-            exec:
-              command:
-              - /var/www/html/phing
-              - -S
-              - warmup
           preStop:
             exec:
               command:
@@ -861,6 +855,55 @@ spec:
         - mountPath: /var/www/html/config/domains_urls.yaml
           name: domains-urls
           subPath: domains_urls.yaml
+      - command:
+        - /var/www/html/phing
+        - -S
+        - warmup
+        env:
+        - name: ELASTICSEARCH_HOST
+          value: http://elasticsearch:9200
+        - name: TRUSTED_PROXY
+          value: 10.0.0.0/8
+        - name: DATABASE_NAME
+          value: myproject-production
+        - name: S3_ENDPOINT
+          value: https://s3.example.com
+        - name: MAILER_FORCE_WHITELIST
+          value: "false"
+        - name: DATABASE_USER
+          value: myproject-production
+        - name: DATABASE_PORT
+          value: "5432"
+        - name: MESSENGER_TRANSPORT_DSN
+          value: amqp://guest:guest@rabbitmq:5672/%2f/messages
+        - name: REDIS_PREFIX
+          value: myproject-production
+        - name: DATABASE_PASSWORD
+          value: test-db-password
+        - name: DATABASE_HOST
+          value: 10.0.0.100
+        - name: ELASTIC_SEARCH_INDEX_PREFIX
+          value: myproject-production
+        - name: SENTRY_RELEASE
+          value: "479411e7"
+        - name: S3_SECRET
+          value: test-s3-secret
+        - name: MAILER_DSN
+          value: smtp://mailhog:1025
+        - name: S3_BUCKET_NAME
+          value: myproject-production
+        - name: S3_ACCESS_KEY
+          value: myproject-production
+        - name: APP_SECRET
+          value: test-app-secret-key
+        image: v1.0.0
+        name: warmup
+        volumeMounts:
+        - mountPath: /var/www/html
+          name: source-codes
+        - mountPath: /var/www/html/config/domains_urls.yaml
+          name: domains-urls
+          subPath: domains_urls.yaml
       terminationGracePeriodSeconds: 120
       volumes:
       - emptyDir: {}
diff --git a/tests/scenarios/production-with-cloudflare/expected/webserver.yaml b/tests/scenarios/production-with-cloudflare/expected/webserver.yaml
index 92cbd9e..af0b676 100644
--- a/tests/scenarios/production-with-cloudflare/expected/webserver.yaml
+++ b/tests/scenarios/production-with-cloudflare/expected/webserver.yaml
@@ -742,12 +742,6 @@ spec:
         image: v2.5.0
         imagePullPolicy: IfNotPresent
         lifecycle:
-          postStart:
-            exec:
-              command:
-              - /var/www/html/phing
-              - -S
-              - warmup
           preStop:
             exec:
               command:
@@ -855,6 +849,53 @@ spec:
         - mountPath: /var/www/html/config/domains_urls.yaml
           name: domains-urls
           subPath: domains_urls.yaml
+      - command:
+        - /var/www/html/phing
+        - -S
+        - warmup
+        env:
+        - name: ELASTICSEARCH_HOST
+          value: http://elasticsearch:9200
+        - name: TRUSTED_PROXY
+          value: 10.0.0.0/8
+        - name: DATABASE_NAME
+          value: shop-production
+        - name: S3_ENDPOINT
+          value: https://s3.example.com
+        - name: MAILER_FORCE_WHITELIST
+          value: "false"
+        - name: DATABASE_USER
+          value: shop-production
+        - name: DATABASE_PORT
+          value: "5432"
+        - name: MESSENGER_TRANSPORT_DSN
+          value: amqp://guest:guest@rabbitmq:5672/%2f/messages
+        - name: REDIS_PREFIX
+          value: shop-production
+        - name: DATABASE_PASSWORD
+          value: test-db-password
+        - name: DATABASE_HOST
+          value: 10.0.0.100
+        - name: ELASTIC_SEARCH_INDEX_PREFIX
+          value: shop-production
+        - name: S3_SECRET
+          value: test-s3-secret
+        - name: MAILER_DSN
+          value: smtp://mailhog:1025
+        - name: S3_BUCKET_NAME
+          value: shop-production
+        - name: S3_ACCESS_KEY
+          value: shop-production
+        - name: APP_SECRET
+          value: test-app-secret-key
+        image: v2.5.0
+        name: warmup
+        volumeMounts:
+        - mountPath: /var/www/html
+          name: source-codes
+        - mountPath: /var/www/html/config/domains_urls.yaml
+          name: domains-urls
+          subPath: domains_urls.yaml
       terminationGracePeriodSeconds: 120
       volumes:
       - emptyDir: {}