diff --git a/.github/workflows/functionaltests.yml b/.github/workflows/functionaltests.yml
index bb09d97..7ac5b2f 100644
--- a/.github/workflows/functionaltests.yml
+++ b/.github/workflows/functionaltests.yml
@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         php-version: [ 7.2, 7.3, 7.4 ]
-        flow-version: [ 6.3, 7.0 ]
+        flow-version: [ 5.3, 6.3, 7.0 ]
         exclude:
           # Disable Flow 7.0 on PHP 7.2, as 7.3 is required
           - php-version: 7.2
diff --git a/.github/workflows/unittests.yml b/.github/workflows/unittests.yml
index 77a6bff..3f26b16 100644
--- a/.github/workflows/unittests.yml
+++ b/.github/workflows/unittests.yml
@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         php-version: [ 7.2, 7.3, 7.4 ]
-        flow-version: [ 6.3, 7.0 ]
+        flow-version: [ 5.3, 6.3, 7.0 ]
         exclude:
           # Disable Flow 7.0 on PHP 7.2, as 7.3 is required
           - php-version: 7.2
diff --git a/composer.json b/composer.json
index 541d0a9..2d10482 100644
--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,7 @@
     "license": "MIT",
     "require": {
         "php": "^7.2",
-        "neos/flow": "^6.3 || ^7.0",
+        "neos/flow": "^5.3 || ^6.3 || ^7.0",
         "sentry/sdk": "^3.1"
     },
     "autoload": {