diff --git a/src/Composer/InstalledVersions.php b/src/Composer/InstalledVersions.php
index 5126c5f8b..8384c86f8 100644
--- a/src/Composer/InstalledVersions.php
+++ b/src/Composer/InstalledVersions.php
@@ -88,7 +88,7 @@ class InstalledVersions
     {
         foreach (self::getInstalled() as $installed) {
             if (isset($installed['versions'][$packageName])) {
-                return $includeDevRequirements || empty($installed['versions'][$packageName]['dev-requirement']);
+                return $includeDevRequirements || empty($installed['versions'][$packageName]['dev_requirement']);
             }
         }
 
@@ -230,7 +230,7 @@ class InstalledVersions
      *
      * @deprecated Use getAllRawData() instead which returns all datasets for all autoloaders present in the process. getRawData only returns the first dataset loaded, which may not be what you expect.
      * @return array[]
-     * @psalm-return array{root: array{name: string, version: string, reference: string, pretty_version: string, aliases: string[], dev: bool}, versions: array<string, array{dev-requirement: bool, pretty_version?: string, version?: string, aliases?: string[], reference?: string, replaced?: string[], provided?: string[]}>}
+     * @psalm-return array{root: array{name: string, version: string, reference: string, pretty_version: string, aliases: string[], dev: bool}, versions: array<string, array{dev_requirement: bool, pretty_version?: string, version?: string, aliases?: string[], reference?: string, replaced?: string[], provided?: string[]}>}
      */
     public static function getRawData()
     {
@@ -266,7 +266,7 @@ class InstalledVersions
      * @param  array[] $data A vendor/composer/installed.php data set
      * @return void
      *
-     * @psalm-param array{root: array{name: string, version: string, reference: string, pretty_version: string, aliases: string[], dev: bool}, versions: array<string, array{dev-requirement: bool, pretty_version?: string, version?: string, aliases?: string[], reference?: string, replaced?: string[], provided?: string[]}>} $data
+     * @psalm-param array{root: array{name: string, version: string, reference: string, pretty_version: string, aliases: string[], dev: bool}, versions: array<string, array{dev_requirement: bool, pretty_version?: string, version?: string, aliases?: string[], reference?: string, replaced?: string[], provided?: string[]}>} $data
      */
     public static function reload($data)
     {
@@ -276,7 +276,7 @@ class InstalledVersions
 
     /**
      * @return array[]
-     * @psalm-return list<array{root: array{name: string, version: string, reference: string, pretty_version: string, aliases: string[], dev: bool}, versions: array<string, array{dev-requirement: bool, pretty_version?: string, version?: string, aliases?: string[], reference?: string, replaced?: string[], provided?: string[]}>}>
+     * @psalm-return list<array{root: array{name: string, version: string, reference: string, pretty_version: string, aliases: string[], dev: bool}, versions: array<string, array{dev_requirement: bool, pretty_version?: string, version?: string, aliases?: string[], reference?: string, replaced?: string[], provided?: string[]}>}>
      */
     private static function getInstalled()
     {
diff --git a/src/Composer/Repository/FilesystemRepository.php b/src/Composer/Repository/FilesystemRepository.php
index 99af09be7..bf2440bc8 100644
--- a/src/Composer/Repository/FilesystemRepository.php
+++ b/src/Composer/Repository/FilesystemRepository.php
@@ -222,11 +222,11 @@ class FilesystemRepository extends WritableArrayRepository
                 'install_path' => $installPath,
                 'aliases' => array(),
                 'reference' => $reference,
-                'dev-requirement' => isset($devPackages[$package->getName()]),
+                'dev_requirement' => isset($devPackages[$package->getName()]),
             );
             if ($package instanceof RootPackageInterface) {
                 $versions['root'] = $versions['versions'][$package->getName()];
-                unset($versions['root']['dev-requirement']);
+                unset($versions['root']['dev_requirement']);
                 $versions['root']['name'] = $package->getName();
                 $versions['root']['dev'] = $devMode;
             }
@@ -240,10 +240,10 @@ class FilesystemRepository extends WritableArrayRepository
                 if (PlatformRepository::isPlatformPackage($replace->getTarget())) {
                     continue;
                 }
-                if (!isset($versions['versions'][$replace->getTarget()]['dev-requirement'])) {
-                    $versions['versions'][$replace->getTarget()]['dev-requirement'] = $isDevPackage;
+                if (!isset($versions['versions'][$replace->getTarget()]['dev_requirement'])) {
+                    $versions['versions'][$replace->getTarget()]['dev_requirement'] = $isDevPackage;
                 } elseif (!$isDevPackage) {
-                    $versions['versions'][$replace->getTarget()]['dev-requirement'] = false;
+                    $versions['versions'][$replace->getTarget()]['dev_requirement'] = false;
                 }
                 $replaced = $replace->getPrettyConstraint();
                 if ($replaced === 'self.version') {
@@ -258,10 +258,10 @@ class FilesystemRepository extends WritableArrayRepository
                 if (PlatformRepository::isPlatformPackage($provide->getTarget())) {
                     continue;
                 }
-                if (!isset($versions['versions'][$provide->getTarget()]['dev-requirement'])) {
-                    $versions['versions'][$provide->getTarget()]['dev-requirement'] = $isDevPackage;
+                if (!isset($versions['versions'][$provide->getTarget()]['dev_requirement'])) {
+                    $versions['versions'][$provide->getTarget()]['dev_requirement'] = $isDevPackage;
                 } elseif (!$isDevPackage) {
-                    $versions['versions'][$provide->getTarget()]['dev-requirement'] = false;
+                    $versions['versions'][$provide->getTarget()]['dev_requirement'] = false;
                 }
                 $provided = $provide->getPrettyConstraint();
                 if ($provided === 'self.version') {