diff --git a/src/ncc/Classes/NccExtension/NccCompiler.php b/src/ncc/Classes/NccExtension/NccCompiler.php
index 8ccdc45..c079ddc 100644
--- a/src/ncc/Classes/NccExtension/NccCompiler.php
+++ b/src/ncc/Classes/NccExtension/NccCompiler.php
@@ -333,6 +333,8 @@
 
             $metadata->addOptions($this->project_manager->getProjectConfiguration()->getBuild()->getOptions($build_configuration));
             $metadata->addOptions($this->project_manager->getProjectConfiguration()->getProject()->getOptions());
+            $metadata->addConstants($this->project_manager->getRuntimeConstants($build_configuration));
+            $metadata->addConstants($this->project_manager->getRuntimeConstants());
             $metadata->setUpdateSource($this->project_manager->getProjectConfiguration()->getProject()->getUpdateSource());
             $metadata->setMainExecutionPolicy($this->project_manager->getProjectConfiguration()->getBuild()->getMain());
             $metadata->setInstaller($this->project_manager->getProjectConfiguration()->getInstaller());
@@ -350,6 +352,7 @@
                 $metadata->removeOption(BuildConfigurationOptions::STATIC_DEPENDENCIES->value);
             }
 
+
             /** @noinspection UnusedFunctionResultInspection */
             $package_writer->setMetadata($metadata);
         }
diff --git a/src/ncc/Classes/Runtime.php b/src/ncc/Classes/Runtime.php
index 6675bca..a324a2d 100644
--- a/src/ncc/Classes/Runtime.php
+++ b/src/ncc/Classes/Runtime.php
@@ -44,9 +44,11 @@
     use ncc\Utilities\Console;
     use ncc\Utilities\IO;
     use ncc\Utilities\Resolver;
+    use ncc\Utilities\RuntimeCache;
     use ncc\Utilities\Validate;
     use RuntimeException;
     use Throwable;
+    use function trigger_error;
 
     class Runtime
     {
@@ -209,6 +211,34 @@
                 }
             }
 
+            $safe_package_name = strtoupper($entry->getAssembly($version)->getName());
+            foreach($entry->getMetadata($version)->getConstants() as $constant => $value)
+            {
+                $constant_full_name = sprintf("%s_%s", $safe_package_name, $constant);
+
+                // Skip if already defined.
+                if(defined($constant_full_name))
+                {
+                    if(RuntimeCache::get(sprintf("defined_%s", $constant_full_name)))
+                    {
+                        continue;
+                    }
+
+                    trigger_error(sprintf('Cannot define constant %s from package %s because the constant is already defined', $constant_full_name, $package), E_USER_WARNING);
+                    continue;
+                }
+
+                if(!Validate::constantName($constant_full_name))
+                {
+                    // trigger warning only
+                    trigger_error(sprintf('Cannot define constant %s from package %s because the constant name is invalid', $constant_full_name, $package), E_USER_WARNING);
+                    continue;
+                }
+
+                RuntimeCache::set(sprintf("defined_%s", $constant_full_name), true);
+                define($constant_full_name, $value);
+            }
+
             if(isset($entry->getMetadata($version)->getOptions()[PackageFlags::STATIC_DEPENDENCIES->value]))
             {
                 // Fake import the dependencies
diff --git a/src/ncc/Managers/ProjectManager.php b/src/ncc/Managers/ProjectManager.php
index 5b7dfe8..58c2b82 100644
--- a/src/ncc/Managers/ProjectManager.php
+++ b/src/ncc/Managers/ProjectManager.php
@@ -203,11 +203,10 @@
          *
          * @param AuthenticationInterface|null $authentication
          * @return array Array of installed packages
-         * @throws OperationException
-         * @throws IOException
          * @throws ConfigurationException
+         * @throws IOException
+         * @throws OperationException
          * @throws PathNotFoundException
-         * @throws NotSupportedException
          */
         public function installDependencies(?AuthenticationInterface $authentication=null): array
         {
@@ -295,7 +294,6 @@
          *
          * @param string $build_configuration
          * @return array
-         * @throws NotSupportedException
          */
         public function getComponents(string $build_configuration=BuildConfigurationValues::DEFAULT->value): array
         {
@@ -311,7 +309,6 @@
          *
          * @param string $build_configuration
          * @return array
-         * @throws NotSupportedException
          */
         public function getResources(string $build_configuration=BuildConfigurationValues::DEFAULT->value): array
         {
@@ -333,11 +330,7 @@
         public function getRuntimeConstants(string $build_configuration=BuildConfigurationValues::DEFAULT->value): array
         {
             $configuration = $this->project_configuration->getBuild()->getBuildConfiguration($build_configuration);
-
-            return array_merge(
-                $configuration->getDefineConstants(),
-                $this->project_configuration->getBuild()->getDefineConstants()
-            );
+            return array_merge($configuration->getDefineConstants(), $this->project_configuration->getBuild()->getDefineConstants());
         }
 
         /**
diff --git a/src/ncc/Objects/Package/Metadata.php b/src/ncc/Objects/Package/Metadata.php
index 1d75e34..95265ea 100644
--- a/src/ncc/Objects/Package/Metadata.php
+++ b/src/ncc/Objects/Package/Metadata.php
@@ -59,6 +59,11 @@
          */
         private $main_execution_policy;
 
+        /**
+         * @var array
+         */
+        private $constants;
+
         /**
          * @var Installer|null
          */
@@ -74,6 +79,7 @@
         {
             $this->compiler_extension = $compiler;
             $this->compiler_version = NCC_VERSION_NUMBER;
+            $this->constants = [];
             $this->options = [];
         }
 
@@ -117,6 +123,27 @@
             $this->compiler_version = $compiler_version;
         }
 
+        /**
+         * Returns the constants associated with the class
+         *
+         * @return array
+         */
+        public function getConstants(): array
+        {
+            return $this->constants;
+        }
+
+        /**
+         * Sets an array of constants to be used within the package
+         *
+         * @param array $constants
+         * @return void
+         */
+        public function addConstants(array $constants): void
+        {
+            $this->constants = array_merge($this->constants, $constants);
+        }
+
         /**
          * Returns an array of options associated with the package
          *
@@ -258,6 +285,7 @@
                 ($bytecode ? Functions::cbc('update_source') : 'update_source') => ($this->update_source?->toArray($bytecode)),
                 ($bytecode ? Functions::cbc('installer') : 'installer') => ($this->installer?->toArray($bytecode)),
                 ($bytecode ? Functions::cbc('main_execution_policy') : 'main_execution_policy') => $this->main_execution_policy,
+                ($bytecode ? Functions::cbc('constants') : 'constants') => $this->constants,
                 ($bytecode ? Functions::cbc('options') : 'options') => $this->options,
             ];
         }
@@ -284,8 +312,14 @@
             $object->options = Functions::array_bc($data, 'options');
             $object->update_source = Functions::array_bc($data, 'update_source');
             $object->main_execution_policy = Functions::array_bc($data, 'main_execution_policy');
+            $object->constants = Functions::array_bc($data, 'constants');
             $object->installer = Functions::array_bc($data, 'installer');
 
+            if($object->constants === null)
+            {
+                $object->constants = [];
+            }
+
             if($object->update_source !== null)
             {
                 $object->update_source = UpdateSource::fromArray($object->update_source);