diff --git a/src/Collection.php b/src/Collection.php
index f971814..7ae3b04 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -27,6 +27,8 @@
  *
  * @template TKey of array-key
  * @template TValue
+ *
+ * @implements IteratorAggregate<TKey, TValue>
  */
 final class Collection implements
     Countable,
diff --git a/src/ComponentInstaller.php b/src/ComponentInstaller.php
index 7ae57a4..bf22f72 100644
--- a/src/ComponentInstaller.php
+++ b/src/ComponentInstaller.php
@@ -478,7 +478,7 @@ private function marshalPackageComponents(array $extra, Collection $packageTypes
      *
      * @param ComposerExtraComponentInstallerArrayType   $extra
      * @param Collection<int,ConfigOption> $options
-     * @return Collection<array-key,non-empty-string> List of packages to install
+     * @return Collection<int,non-empty-string> List of packages to install
      */
     private function marshalInstallableComponents(array $extra, Collection $options): Collection
     {
@@ -658,9 +658,10 @@ private function removePackageFromConfig(string $package, array $metadata): void
     /**
      * Remove an individual module defined in a package from configuration.
      *
-     * @param non-empty-string     $component Module to remove
+     * @template TKey of array-key
+     * @param non-empty-string $component Module to remove
      * @param non-empty-string $package   Package in which module is defined
-     * @param Collection<array-key,InjectorInterface> $injectors Injectors to use for removal
+     * @param Collection<TKey,InjectorInterface> $injectors Injectors to use for removal
      */
     private function removeModuleFromConfig(string $component, string $package, Collection $injectors): void
     {
diff --git a/src/ConfigDiscovery.php b/src/ConfigDiscovery.php
index ed01b6e..6a03099 100644
--- a/src/ConfigDiscovery.php
+++ b/src/ConfigDiscovery.php
@@ -49,7 +49,8 @@ final class ConfigDiscovery
     /**
      * Return a list of available configuration options.
      *
-     * @param Collection<array-key,InjectorInterface::TYPE_*> $availableTypes Collection of injector type
+     * @template TKey of array-key
+     * @param Collection<TKey,InjectorInterface::TYPE_*> $availableTypes Collection of injector type
      *     constants indicating valid package types that could be injected.
      * @param string $projectRoot Path to the project root; assumes PWD by default.
      * @return Collection<int,ConfigOption> Collection of ConfigOption instances.
diff --git a/src/ConfigDiscovery/DiscoveryChain.php b/src/ConfigDiscovery/DiscoveryChain.php
index 82e14ae..4b1084b 100644
--- a/src/ConfigDiscovery/DiscoveryChain.php
+++ b/src/ConfigDiscovery/DiscoveryChain.php
@@ -14,7 +14,7 @@ final class DiscoveryChain implements DiscoveryChainInterface
     /**
      * Discovery Collection
      *
-     * @var Collection<array-key,DiscoveryInterface>
+     * @var Collection<string,DiscoveryInterface>
      */
     protected Collection $chain;
 
@@ -27,7 +27,7 @@ final class DiscoveryChain implements DiscoveryChainInterface
     public function __construct(array $discovery, string $projectDirectory = '')
     {
         $this->chain = (new Collection($discovery))
-            // Create a discovery class for the dicovery type
+            // Create a discovery class for the discovery type
             ->map(static fn(string $discoveryClass) => new $discoveryClass($projectDirectory))
             // Use only those where we can locate a corresponding config file
             ->filter(static fn(DiscoveryInterface $discovery) => $discovery->locate());
diff --git a/src/Injector/ConfigInjectorChain.php b/src/Injector/ConfigInjectorChain.php
index 76b10f2..34dcf21 100644
--- a/src/Injector/ConfigInjectorChain.php
+++ b/src/Injector/ConfigInjectorChain.php
@@ -22,7 +22,7 @@ final class ConfigInjectorChain implements InjectorInterface
     /**
      * ConfigInjectors Collection
      *
-     * @var Collection<array-key,InjectorInterface>
+     * @var Collection<string,InjectorInterface>
      */
     private Collection $chain;
 
@@ -135,7 +135,7 @@ public function remove(string $package): bool
     }
 
     /**
-     * @return Collection<array-key,InjectorInterface>
+     * @return Collection<string,InjectorInterface>
      */
     public function getCollection(): Collection
     {