diff --git a/src/Resolve.php b/src/Resolve.php
index c16c5d9..219b2fb 100644
--- a/src/Resolve.php
+++ b/src/Resolve.php
@@ -6,6 +6,7 @@
 use ReflectionClass;
 use ReflectionException;
 use ReflectionFunction;
+use ReflectionNamedType;
 use ReflectionObject;
 use ReflectionParameter;
 
@@ -74,59 +75,71 @@ function(ReflectionParameter $reflectionParameter) use ($container, $parameters)
 					return $parameters[$parameter_name];
 				}
 
-				$parameter_type = $reflectionParameter->getType();
+				$reflectionType = $reflectionParameter->getType();
 
-				if( $parameter_type instanceof \ReflectionNamedType === false ) {
-					throw new ParameterResolutionException("Cannot resolve union or intersection types");
+				if( empty($reflectionType) ){
+					throw new ParameterResolutionException("Cannot resolve parameter with no type.");
 				}
 
-				/**
-				 * Check container and parameters for a match by type.
-				 */
-				if( !$parameter_type->isBuiltin() ) {
+				if( $reflectionType instanceof \ReflectionIntersectionType ){
+					throw new ParameterResolutionException("Cannot resolve intersection types.");
+				}
+				elseif( $reflectionType instanceof \ReflectionNamedType ){
+					$reflectionType = [$reflectionType];
+				}
+				elseif( $reflectionType instanceof \ReflectionUnionType ){
+					$reflectionType = $reflectionType->getTypes();
+				}
 
-					if( $container && $container->has($parameter_type->getName()) ){
-						return $container->get($parameter_type->getName());
-					}
+				foreach( $reflectionType as $parameter_type ){
+					/**
+					 * Check container and parameters for a match by type.
+					 */
+					if( !$parameter_type->isBuiltin() ) {
 
-					// Try to find in the parameters supplied
-					$match = \array_filter(
-						$parameters,
-						function($parameter) use ($parameter_type): bool {
-							$parameter_type_name = $parameter_type->getName();
-							return $parameter instanceof $parameter_type_name;
+						if( $container && $container->has($parameter_type->getName()) ){
+							return $container->get($parameter_type->getName());
 						}
-					);
 
-					if( $match ){
-						return $match[
-							\array_keys($match)[0]
-						];
-					}
+						// Try to find in the parameters supplied
+						$match = \array_filter(
+							$parameters,
+							function($parameter) use ($parameter_type): bool {
+								$parameter_type_name = $parameter_type->getName();
+								return $parameter instanceof $parameter_type_name;
+							}
+						);
 
-					try {
+						if( $match ){
+							return $match[
+								\array_keys($match)[0]
+							];
+						}
 
-						return $this->make(
-							$parameter_type->getName(),
-							$container,
-							$parameters
-						);
+						try {
+
+							return $this->make(
+								$parameter_type->getName(),
+								$container,
+								$parameters
+							);
+						}
+						catch( \Exception $exception ){}
 					}
-					catch( \Exception $exception ){}
-				}
 
-				/**
-				 * If a default value is defined, use that, including a null value.
-				 */
-				if( $reflectionParameter->isDefaultValueAvailable() ){
-					return $reflectionParameter->getDefaultValue();
-				}
-				elseif( $reflectionParameter->allowsNull() ){
-					return null;
-				}
+					/**
+					 * If a default value is defined, use that, including a null value.
+					 */
+					if( $reflectionParameter->isDefaultValueAvailable() ){
+						return $reflectionParameter->getDefaultValue();
+					}
+					elseif( $reflectionParameter->allowsNull() ){
+						return null;
+					}
 
-				if( !empty($exception) ){
-					throw $exception;
+					if( !empty($exception) ){
+						throw $exception;
+					}
 				}
 
 				throw new ParameterResolutionException("Cannot resolve parameter \"{$parameter_name}\".");
diff --git a/tests/ResolveTest.php b/tests/ResolveTest.php
index 0b426c9..2b58153 100644
--- a/tests/ResolveTest.php
+++ b/tests/ResolveTest.php
@@ -562,7 +562,7 @@ public function test_resolve_reflection_parameters_with_making_class_with_constr
 		);
 	}
 
-	public function test_resolve_reflection_parameters_with_non_reflection_named_type_throws_parameter_resolution_exception(): void
+	public function test_resolve_reflection_parameters_with_union_type(): void
 	{
 		$resolve = new class {
 			use Resolve;
@@ -572,7 +572,37 @@ public function test_resolve_reflection_parameters_with_non_reflection_named_typ
 		$reflectionMethod = $reflectionClass->getMethod("resolveReflectionParameters");
 		$reflectionMethod->setAccessible(true);
 
-		$callable = function(DateTime|DateTimeImmutable $dateTime): void {
+		$callable = function(DateTime|DateTimeImmutable $dateTime): string {
+			return "The date is now: " . $dateTime->format("c");
+		};
+
+		$dateTime = new DateTimeImmutable("2020-01-28T12:00:01-08:00");
+
+		$reflectionFunction = new ReflectionFunction($callable);
+		$result = $reflectionMethod->invoke(
+			$resolve,
+			$reflectionFunction->getParameters(),
+			null,
+			["dateTime" => $dateTime]
+		);
+
+		$this->assertSame(
+			$dateTime,
+			$result[0]
+		);
+	}
+
+	public function test_resolve_reflection_parameters_with_intersection_type_throws_parameter_resolution_exception(): void
+	{
+		$resolve = new class {
+			use Resolve;
+		};
+
+		$reflectionClass = new ReflectionClass($resolve);
+		$reflectionMethod = $reflectionClass->getMethod("resolveReflectionParameters");
+		$reflectionMethod->setAccessible(true);
+
+		$callable = function(DateTime&DateTimeImmutable $dateTime): void {
 			echo "The date is now: " . $dateTime;
 		};