diff --git a/initializr-generator/src/main/groovy/io/spring/initializr/generator/ProjectRequest.groovy b/initializr-generator/src/main/groovy/io/spring/initializr/generator/ProjectRequest.groovy
index ba75efd6..1baa2ac0 100644
--- a/initializr-generator/src/main/groovy/io/spring/initializr/generator/ProjectRequest.groovy
+++ b/initializr-generator/src/main/groovy/io/spring/initializr/generator/ProjectRequest.groovy
@@ -78,12 +78,7 @@ class ProjectRequest extends BasicProjectRequest {
 		resolvedDependencies = depIds.collect {
 			def dependency = metadata.dependencies.get(it)
 			if (dependency == null) {
-				if (it.contains(':')) {
-					throw new InvalidProjectRequestException("Unknown dependency '$it' check project metadata")
-				}
-				log.warn("No known dependency for style '$it' assuming spring-boot-starter")
-				dependency = new Dependency()
-				dependency.asSpringBootStarter(it)
+				throw new InvalidProjectRequestException("Unknown dependency '$it' check project metadata")
 			}
 			dependency.resolve(requestedVersion)
 		}
diff --git a/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectGeneratorTests.groovy b/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectGeneratorTests.groovy
index 1c11f778..54a62c5f 100644
--- a/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectGeneratorTests.groovy
+++ b/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectGeneratorTests.groovy
@@ -550,6 +550,18 @@ class ProjectGeneratorTests extends AbstractProjectGeneratorTests {
 				.hasDependenciesCount(3)
 	}
 
+	@Test
+	void invalidDependency() {
+		def request = createProjectRequest('foo-bar')
+		try {
+			generateMavenPom(request)
+			fail("Should have failed to generate project")
+		} catch (InvalidProjectRequestException ex) {
+			assertThat ex.message, containsString('foo-bar')
+			verifyProjectFailedEventFor(request, ex)
+		}
+	}
+
 	@Test
 	void invalidType() {
 		def request = createProjectRequest('web')
diff --git a/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectRequestTests.groovy b/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectRequestTests.groovy
index 616ed70a..55f7779a 100644
--- a/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectRequestTests.groovy
+++ b/initializr-generator/src/test/groovy/io/spring/initializr/generator/ProjectRequestTests.groovy
@@ -100,15 +100,17 @@ class ProjectRequestTests {
 	}
 
 	@Test
-	void resolveUnknownSimpleIdAsSpringBootStarter() {
+	void resolveUnknownSimpleId() {
 		def request = new ProjectRequest()
 		def metadata = InitializrMetadataTestBuilder.withDefaults()
 				.addDependencyGroup('code', 'org.foo:bar').build()
 
 		request.style << 'org.foo:bar' << 'foo-bar'
+
+		thrown.expect(InvalidProjectRequestException)
+		thrown.expectMessage('foo-bar')
 		request.resolve(metadata)
-		assertDependency(request.resolvedDependencies[0], 'org.foo', 'bar', null)
-		assertBootStarter(request.resolvedDependencies[1], 'foo-bar')
+		assertEquals(1, request.resolvedDependencies.size())
 	}
 
 	@Test
diff --git a/initializr-web/src/main/groovy/io/spring/initializr/web/project/AbstractInitializrController.groovy b/initializr-web/src/main/groovy/io/spring/initializr/web/project/AbstractInitializrController.groovy
index 56b2e777..e44632f1 100644
--- a/initializr-web/src/main/groovy/io/spring/initializr/web/project/AbstractInitializrController.groovy
+++ b/initializr-web/src/main/groovy/io/spring/initializr/web/project/AbstractInitializrController.groovy
@@ -17,6 +17,7 @@
 package io.spring.initializr.web.project
 
 import javax.annotation.PostConstruct
+import javax.servlet.http.HttpServletResponse
 
 import io.spring.initializr.generator.InvalidProjectRequestException
 import io.spring.initializr.metadata.InitializrMetadataProvider
@@ -24,7 +25,6 @@ import io.spring.initializr.metadata.InitializrMetadataProvider
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.http.HttpStatus
 import org.springframework.web.bind.annotation.ExceptionHandler
-import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.servlet.support.ServletUriComponentsBuilder
 
 import static io.spring.initializr.util.GroovyTemplate.template
@@ -47,10 +47,9 @@ abstract class AbstractInitializrController {
 		forceSsl = metadataProvider.get().configuration.env.forceSsl
 	}
 
-	@ExceptionHandler(InvalidProjectRequestException)
-	@ResponseStatus(value= HttpStatus.BAD_REQUEST)
-	public void invalidProjectVersion() {
-		// Nothing to do
+	@ExceptionHandler
+	public void invalidProjectRequest(HttpServletResponse response, InvalidProjectRequestException ex) {
+		response.sendError(HttpStatus.BAD_REQUEST.value(), ex.getMessage());
 	}
 
 	/**
diff --git a/initializr-web/src/test/groovy/io/spring/initializr/web/project/MainControllerIntegrationTests.groovy b/initializr-web/src/test/groovy/io/spring/initializr/web/project/MainControllerIntegrationTests.groovy
index 2db4e236..7f63b9c4 100644
--- a/initializr-web/src/test/groovy/io/spring/initializr/web/project/MainControllerIntegrationTests.groovy
+++ b/initializr-web/src/test/groovy/io/spring/initializr/web/project/MainControllerIntegrationTests.groovy
@@ -16,10 +16,10 @@
 
 package io.spring.initializr.web.project
 
+import groovy.json.JsonSlurper
 import io.spring.initializr.metadata.Dependency
 import io.spring.initializr.web.AbstractInitializrControllerIntegrationTests
 import io.spring.initializr.web.mapper.InitializrMetadataVersion
-import io.spring.initializr.web.project.MainController
 import org.json.JSONObject
 import org.junit.Ignore
 import org.junit.Test
@@ -41,6 +41,7 @@ import static org.junit.Assert.assertFalse
 import static org.junit.Assert.assertNotNull
 import static org.junit.Assert.assertThat
 import static org.junit.Assert.assertTrue
+import static org.junit.Assert.fail
 
 /**
  * @author Stephane Nicoll
@@ -326,15 +327,24 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 	void missingDependencyProperException() {
 		try {
 			downloadArchive('/starter.zip?style=foo:bar')
+			fail("Should have failed")
 		} catch (HttpClientErrorException ex) {
 			assertEquals HttpStatus.BAD_REQUEST, ex.getStatusCode()
+			assertStandardErrorBody(ex.getResponseBodyAsString(),
+					"Unknown dependency 'foo:bar' check project metadata")
 		}
-
 	}
 
 	@Test
-	void downloadWithUnknownSpringBootStarter() { // Simple id are accepted as spring-boot-starter
-		downloadZip('/starter.zip?style=foo').pomAssert().hasSpringBootStarterDependency('foo')
+	void invalidDependencyProperException() {
+		try {
+			downloadArchive('/starter.zip?style=foo')
+			fail("Should have failed")
+		} catch (HttpClientErrorException ex) {
+			assertEquals HttpStatus.BAD_REQUEST, ex.getStatusCode()
+			assertStandardErrorBody(ex.getResponseBodyAsString(),
+					"Unknown dependency 'foo' check project metadata")
+		}
 	}
 
 	@Test
@@ -412,5 +422,10 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 		return new JSONObject(json)
 	}
 
+	private static void assertStandardErrorBody(String body, String message) {
+		assertNotNull "error body must be available", body
+		def model = new JsonSlurper().parseText(body)
+		assertEquals message, model.message
+	}
 
 }