diff --git a/src/test/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSessionCacheTest.java b/src/test/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSessionCacheTest.java
index 22401d1..80f818d 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSessionCacheTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSessionCacheTest.java
@@ -18,7 +18,12 @@
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.gerrit.httpd.WebSessionManager;
 import com.google.gerrit.httpd.WebSessionManager.Val;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.inject.AbstractModule;
+import com.google.inject.Guice;
+import com.google.inject.Injector;
 import com.googlesource.gerrit.plugins.websession.flatfile.FlatFileWebSessionCache.TimeMachine;
 import java.io.IOException;
 import java.io.InputStream;
@@ -33,6 +38,8 @@
 import java.util.Map;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
+
+import org.eclipse.jgit.lib.Config;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -50,6 +57,18 @@
   private FlatFileWebSessionCache cache;
   private Path websessionDir;
 
+  private static final Injector injector = Guice.createInjector(new TestModule());
+  static class TestModule extends AbstractModule {
+    @Override
+    protected void configure() {
+      // GerritServerConfig is required by WebSessionManager
+      bind(Config.class).annotatedWith(GerritServerConfig.class).toInstance(new Config());
+      // Static injection should be avoided if possible, however this is the implementation
+      // currently used in Gerrit core (see change I64db5ed5256564dbc03952e9721615f42212ad48)
+      requestStaticInjection(WebSessionManager.Val.class);
+    }
+  }
+
   @Before
   public void createFlatFileWebSessionCache() throws Exception {
     websessionDir = tempFolder.newFolder("websessions").toPath();