diff --git a/src/main/java/org/springframework/guice/GuiceModuleMetadata.java b/src/main/java/org/springframework/guice/GuiceModuleMetadata.java
index 499b83a..2555353 100644
--- a/src/main/java/org/springframework/guice/GuiceModuleMetadata.java
+++ b/src/main/java/org/springframework/guice/GuiceModuleMetadata.java
@@ -104,7 +104,7 @@ public class GuiceModuleMetadata {
 	private boolean visible(Class<?> type) {
 		Class<?> cls = type;
 		while (cls != null && cls != Object.class) {
-			if (!Modifier.isPublic(cls.getModifiers())) {
+			if (!Modifier.isInterface(cls.getModifiers()) && !Modifier.isPublic(cls.getModifiers()) && !Modifier.isProtected(cls.getModifiers())) {
 				return false;
 			}
 			cls = cls.getDeclaringClass();
diff --git a/src/test/java/org/springframework/guice/SpringModuleMetadataTests.java b/src/test/java/org/springframework/guice/SpringModuleMetadataTests.java
index 76da586..22c005a 100644
--- a/src/test/java/org/springframework/guice/SpringModuleMetadataTests.java
+++ b/src/test/java/org/springframework/guice/SpringModuleMetadataTests.java
@@ -13,6 +13,7 @@
 
 package org.springframework.guice;
 
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 
 import javax.inject.Inject;
@@ -28,6 +29,7 @@ import org.springframework.core.type.filter.AnnotationTypeFilter;
 import org.springframework.core.type.filter.AssignableTypeFilter;
 
 import com.google.inject.ConfigurationException;
+import com.google.inject.CreationException;
 import com.google.inject.Guice;
 import com.google.inject.Injector;
 
@@ -43,8 +45,15 @@ public class SpringModuleMetadataTests {
 	@Test
 	public void twoConfigClasses() throws Exception {
 		Injector injector = createInjector(TestConfig.class, OtherConfig.class);
-		expected.expect(ConfigurationException.class);
-		assertNull(injector.getBinding(Service.class));
+		assertNotNull(injector.getBinding(Service.class));
+	}
+
+	@Test
+	public void twoServices() throws Exception {
+		// Two beans with the same interface cause problems at startup
+		expected.expect(CreationException.class);
+		Injector injector = createInjector(TestConfig.class, MoreConfig.class);
+		assertNotNull(injector.getBinding(Service.class));
 	}
 
 	@Test
@@ -111,6 +120,14 @@ public class SpringModuleMetadataTests {
 		}
 	}
 
+	@Configuration
+	public static class MoreConfig {
+		@Bean
+		public Service more() {
+			return new MyService();
+		}
+	}
+
 	@Configuration
 	public static class OtherConfig {
 	}