diff --git a/.travis.yml b/.travis.yml
index 5e69d79..2f2f25c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ php:
   - 7.1
   - 7.2
   - 7.3
+  - 7.4
   - hhvm
   - nightly
 
diff --git a/Makefile b/Makefile
index 93f0b0c..ee0539b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,7 @@
 test: test-phpunit
 test-phpunit:
-	PHP_VERSION=7.3 docker-compose run --rm php php -v && php vendor/bin/phpunit --coverage-text
+	PHP_VERSION=7.4 docker-compose run --rm php php -v
+	PHP_VERSION=7.4 docker-compose run --rm php php vendor/bin/phpunit --coverage-text
 test-phpunit-local:
 	php -v
 	php vendor/bin/phpunit --coverage-text
@@ -9,7 +10,8 @@ travis:
 	PHP_VERSION=7.1 make travis-job
 	PHP_VERSION=7.2 make travis-job
 	PHP_VERSION=7.3 make travis-job
-	PHP_VERSION=7.3 docker-compose run --rm composer composer config --unset platform
+	PHP_VERSION=7.4 make travis-job
+	PHP_VERSION=7.4 docker-compose run --rm composer composer config --unset platform
 travis-job:
 	docker-compose run --rm composer composer config platform.php ${PHP_VERSION}
 	docker-compose run --rm composer composer update -q
diff --git a/composer.json b/composer.json
index 8cd62c5..1f31a9a 100644
--- a/composer.json
+++ b/composer.json
@@ -11,7 +11,7 @@
         }
     ],
     "require": {
-        "php": "^7.1"
+        "php": "^7.1|^8.0"
     },
     "require-dev": {
         "ext-json": "*",
diff --git a/src/Enum/EnumTrait.php b/src/Enum/EnumTrait.php
index a2c82e7..416b3e8 100644
--- a/src/Enum/EnumTrait.php
+++ b/src/Enum/EnumTrait.php
@@ -210,7 +210,9 @@ final private static function resolveMembers(): void
             return;
         }
 
-        if(false === method_exists($class, 'resolve')) {
+        // reflection instead of method_exists because of PHP 7.4 bug #78632
+        // @see https://bugs.php.net/bug.php?id=78632
+        if(false === (new \ReflectionClass($class))->hasMethod('resolve')) {
             throw PlatenumException::fromMissingResolve($class);
         }
         $members = static::resolve();
diff --git a/src/Enum/StaticEnumTrait.php b/src/Enum/StaticEnumTrait.php
index 17a760d..cf8e7fa 100644
--- a/src/Enum/StaticEnumTrait.php
+++ b/src/Enum/StaticEnumTrait.php
@@ -14,7 +14,9 @@ trait StaticEnumTrait
     final private static function resolve(): array
     {
         $class = static::class;
-        if(false === property_exists($class, 'mapping')) {
+        // reflection instead of property_exists because of PHP 7.4 bug #78632
+        // @see https://bugs.php.net/bug.php?id=78632
+        if(false === (new \ReflectionClass($class))->hasProperty('mapping')) {
             throw PlatenumException::fromMissingMappingProperty($class);
         }