diff --git a/core/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryTest.java b/core/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryTest.java
index 5b8ba795..20948d8f 100644
--- a/core/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryTest.java
+++ b/core/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryTest.java
@@ -95,7 +95,7 @@ void findServiceOriginsSingleJar() throws IOException
         Files.createFile(pluginDir.resolve("plugin1.jar"));
         final List<ServiceOrigin> origins = testee().findServiceOrigins();
         assertAll(() -> assertThat(origins, hasSize(2)),
-                () -> assertThat(origins.get(1).getClassLoader().getName(), equalTo("ServiceClassLoader-plugin1.jar")));
+                () -> assertThat(origins.get(0).getClassLoader().getName(), equalTo("JarClassLoader-plugin1.jar")));
     }
 
     @Test
@@ -107,8 +107,8 @@ void findServiceOriginsMultiJar() throws IOException
         Files.createFile(pluginDir.resolve("plugin2.jar"));
         final List<ServiceOrigin> origins = testee().findServiceOrigins();
         assertAll(() -> assertThat(origins, hasSize(2)),
-                () -> assertThat(origins.get(1).getClassLoader().getName(),
-                        equalTo("ServiceClassLoader-plugin1.jar,plugin2.jar")));
+                () -> assertThat(origins.get(0).getClassLoader().getName(),
+                        equalTo("JarClassLoader-plugin1.jar,plugin2.jar")));
     }
 
     @Test
@@ -122,9 +122,9 @@ void findServiceOriginsMultiPlugins() throws IOException
         Files.createFile(pluginDir2.resolve("plugin2.jar"));
         final List<ServiceOrigin> origins = testee().findServiceOrigins();
         assertAll(() -> assertThat(origins, hasSize(3)),
+                () -> assertThat(origins.get(0).getClassLoader().getName(),
+                        equalTo("JarClassLoader-plugin1.jar")),
                 () -> assertThat(origins.get(1).getClassLoader().getName(),
-                        equalTo("ServiceClassLoader-plugin1.jar")),
-                () -> assertThat(origins.get(2).getClassLoader().getName(),
-                        equalTo("ServiceClassLoader-plugin2.jar")));
+                        equalTo("JarClassLoader-plugin2.jar")));
     }
 }
diff --git a/product/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryIT.java b/product/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryIT.java
index 94b15a72..d17cb430 100644
--- a/product/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryIT.java
+++ b/product/src/test/java/org/itsallcode/openfasttrace/core/serviceloader/ServiceLoaderFactoryIT.java
@@ -59,7 +59,7 @@ void loadServiceFromJar() throws IOException
                     () -> assertThat(service.getClass().getName().toString(),
                             equalTo("org.itsallcode.openfasttrace.report.plaintext.PlaintextReporterFactory")),
                     () -> assertThat(pluginClassLoader.getName(),
-                            startsWith("ServiceClassLoader-openfasttrace-reporter-plaintext")),
+                            startsWith("JarClassLoader-openfasttrace-reporter-plaintext")),
                     () -> assertThat(pluginClassLoader,
                             not(sameInstance(Thread.currentThread().getContextClassLoader()))));
         }
@@ -69,7 +69,8 @@ private void preparePlugin(final Path targetDir, final String filePattern) throw
     {
         final Path jar = findMatchingFile(targetDir, filePattern)
                 .orElseThrow(() -> new AssertionError(
-                        "Did not file matching '" + filePattern + "' in '" + targetDir + "'"));
+                        "Did not file matching '" + filePattern + "' in '" + targetDir
+                                + "'. Ensure the module was built with 'mvn package'."));
         preparePlugin(jar);
     }