diff --git a/scm-webapp/src/main/java/sonia/scm/plugin/PluginProcessor.java b/scm-webapp/src/main/java/sonia/scm/plugin/PluginProcessor.java
index 5ae4a32897..fced7a01ed 100644
--- a/scm-webapp/src/main/java/sonia/scm/plugin/PluginProcessor.java
+++ b/scm-webapp/src/main/java/sonia/scm/plugin/PluginProcessor.java
@@ -59,6 +59,9 @@ import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Predicate;
+
+import static java.util.stream.Collectors.toList;
 
 //~--- JDK imports ------------------------------------------------------------
 
@@ -68,6 +71,7 @@ import java.util.Set;
  *
  * TODO don't mix nio and io
  */
+@SuppressWarnings("squid:S3725") // performance is not critical, for this type of checks
 public final class PluginProcessor
 {
 
@@ -171,7 +175,11 @@ public final class PluginProcessor
 
     extract(archives);
 
-    List<Path> dirs = collectPluginDirectories(pluginDirectory);
+    List<Path> dirs =
+      collectPluginDirectories(pluginDirectory)
+      .stream()
+      .filter(isPluginDirectory())
+      .collect(toList());
 
     logger.debug("process {} directories: {}", dirs.size(), dirs);
 
@@ -194,6 +202,10 @@ public final class PluginProcessor
     return ImmutableSet.copyOf(wrappers);
   }
 
+  private Predicate<Path> isPluginDirectory() {
+    return dir -> Files.exists(dir.resolve(DIRECTORY_METAINF).resolve("scm").resolve("plugin.xml"));
+  }
+
   /**
    * Method description
    *
diff --git a/scm-webapp/src/test/java/sonia/scm/plugin/PluginProcessorTest.java b/scm-webapp/src/test/java/sonia/scm/plugin/PluginProcessorTest.java
index 0fbf7eabbc..dc5a9add68 100644
--- a/scm-webapp/src/test/java/sonia/scm/plugin/PluginProcessorTest.java
+++ b/scm-webapp/src/test/java/sonia/scm/plugin/PluginProcessorTest.java
@@ -134,6 +134,16 @@ public class PluginProcessorTest
     assertThat(plugin.getId(), is(PLUGIN_A.id));
   }
 
+  @Test
+  public void shouldCollectPluginsAndDoNotFailOnNonPluginDirectories() throws IOException {
+    new File(pluginDirectory, "some-directory").mkdirs();
+
+    copySmp(PLUGIN_A);
+    PluginWrapper plugin = collectAndGetFirst();
+
+    assertThat(plugin.getId(), is(PLUGIN_A.id));
+  }
+
   /**
    * Method description
    *