diff --git a/.travis.yml b/.travis.yml
index 887534f..4fa831b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,17 +6,12 @@ services:
     - docker
 
 php:
-    - 7.0
-    - 7.1
     - 7.2
+    - 7.3
+    - 7.4
     - nightly
 
 env:
-    matrix:
-        - COMPOSERFLAGS=
-        - COMPOSERFLAGS=--prefer-lowest
-        - COMPOSERFLAGS=--prefer-stable
-
     global:
         # DOCKER_EMAIL
         - secure: 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
@@ -26,15 +21,6 @@ env:
         - secure: "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"
 
 matrix:
-    exclude:
-        - php: 7.0
-          env: COMPOSERFLAGS=
-        - php: 7.1
-          env: COMPOSERFLAGS=--prefer-lowest
-        - php: 7.2
-          env: COMPOSERFLAGS=--prefer-lowest
-        - php: nightly
-          env: COMPOSERFLAGS=--prefer-lowest
     allow_failures:
         - php: nightly
 
@@ -45,10 +31,10 @@ deploy:
     - provider: script
       script: ci/deploy.sh
       on:
-          php: 7.1
+          php: 7.4
           all_branches: master
     - provider: script
       script: ci/deploy.sh
       on:
-          php: 7.1
+          php: 7.4
           tags: true
diff --git a/Dockerfile b/Dockerfile
index 483742c..0762663 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,16 @@
-FROM php:7.1-alpine
+FROM php:7.4-alpine as builder
+
+COPY composer.json /dcv/composer.json
+COPY composer.lock /dcv/composer.lock
+
+WORKDIR /dcv
+
+RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" && \
+    php composer-setup.php && \
+    php -r "unlink('composer-setup.php');" && \
+    php composer.phar install --prefer-dist
+
+FROM php:7.4-alpine
 
 RUN apk update && \
     apk add graphviz ttf-dejavu && \
@@ -8,7 +20,7 @@ RUN apk update && \
 
 COPY bin/    /dcv/bin
 COPY src/    /dcv/src
-COPY vendor/ /dcv/vendor
+COPY --from=builder /dcv/vendor /dcv/vendor
 
 RUN chmod +x /dcv/bin/dcv
 
diff --git a/Makefile b/Makefile
index c33f710..e75f6b6 100644
--- a/Makefile
+++ b/Makefile
@@ -24,17 +24,11 @@ clean:
 	rm -rf vendor/
 
 docker.lock: Dockerfile bin/entrypoint.sh vendor src/application.php src/functions.php
-	$(COMPOSER) dump-autoload --classmap-authoritative
 	$(DOCKER) build -t $(DCV_IMAGE_NAME) .
 	touch docker.lock
 
-ifndef COMPOSERFLAGS
 vendor: composer.lock
 	$(COMPOSER) install --prefer-dist
-else
-vendor: composer.lock
-	$(COMPOSER) update $(COMPOSERFLAGS)
-endif
 
 composer.lock: composer.json
 	$(COMPOSER) update $(COMPOSERFLAGS)
diff --git a/README.md b/README.md
index 304d7cf..488d518 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ This will generate the `docker-compose.png` file in the current working director
 Before you start, make sure you have:
 
 * [Composer](https://getcomposer.org/doc/00-intro.md#installation-linux-unix-osx) installed,
-* [PHP 7](http://php.net/downloads.php#v7.0.9) installed,
+* [PHP 7.2](http://php.net/downloads.php#v7.2.32) (at least) installed,
 * GraphViz installed (see below for a guide on how to install it)
 
 ```
diff --git a/composer.json b/composer.json
index 03e7e03..dc4dae5 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,7 @@
     "name": "pmsipilot/docker-compose-viz",
     "description": "Docker compose graph visualization",
     "require": {
-        "php": "^7",
+        "php": "^7.2",
         "symfony/yaml": "^3.1 || ^4",
         "symfony/console": "^3.1",
         "clue/graph": "^0.9",
diff --git a/composer.lock b/composer.lock
index 167dcbc..c2a23f3 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "e5370b9d4f890699543b1dbd6ba801de",
+    "content-hash": "b969fd3f88d63984295c01f8c964a703",
     "packages": [
         {
             "name": "clue/graph",
@@ -1721,7 +1721,7 @@
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": {
-        "php": "^7"
+        "php": "^7.2"
     },
     "platform-dev": []
 }