diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 72ef5508..ec537aa8 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -12,6 +12,8 @@ jobs:
   Tests:
     runs-on: ubuntu-latest
     continue-on-error: ${{ matrix.experimental == true }}
+    env:
+      SYMFONY_REQUIRE: ${{matrix.symfony_constraint}}
     strategy:
       fail-fast: false
       matrix:
@@ -21,7 +23,7 @@ jobs:
           - '7.3'
           - '7.2'
         sentry_constraint: [false]
-        symfony_constraint: [false]
+        symfony_constraint: ['']
         experimental: [false]
         include:
 #          - description: 'sentry/sentry dev-develop'
@@ -55,9 +57,8 @@ jobs:
         with:
           php-version: ${{ matrix.php }}
           coverage: xdebug
-      - run: |
-          sed -ri '/symfony\/(monolog-bundle|phpunit-bridge|messenger|psr-http-message-bridge|polyfill-php80)/! s/"symfony\/(.+)": "(.+)"/"symfony\/\1": "'${{ matrix.symfony_constraint }}'"/' composer.json;
-        if: matrix.symfony_constraint
+      - name: Install Symfony Flex
+        run: composer global require --no-progress --no-scripts --no-plugins symfony/flex
       - run: composer remove --dev symfony/messenger --no-update
         if: matrix.symfony_constraint == '3.4.*' || matrix.composer_option == '--prefer-lowest'
       - run: composer update --no-progress --ansi ${{ matrix.composer_option }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index acb3d19d..eebd23cb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 - Add support for distributed tracing when running a console command (#455)
 - Added missing `capture-soft-fails` config schema option (#417)
 - Deprecate the `Sentry\SentryBundle\EventListener\ConsoleCommandListener` class in favor of its parent class `Sentry\SentryBundle\EventListener\ConsoleListener` (#429)
+- Lower the required version of `symfony/psr-http-message-bridge` to allow installing it on a project that uses Symfony `3.4.x` components only (#480)
 
 ## 4.0.3 (2021-03-03)
 - Fix regression from #454 for `null` value on DSN not disabling Sentry (#457)
diff --git a/composer.json b/composer.json
index fe187d81..ca862c28 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
         "symfony/event-dispatcher": "^3.4.44||^4.4.20||^5.0.11",
         "symfony/http-kernel": "^3.4.44||^4.4.20||^5.0.11",
         "symfony/polyfill-php80": "^1.22",
-        "symfony/psr-http-message-bridge": "^2.0",
+        "symfony/psr-http-message-bridge": "^1.2||^2.0",
         "symfony/security-core": "^3.4.44||^4.4.20||^5.0.11"
     },
     "require-dev": {