diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d8fd79db9..5421312a13 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Fixed 
+- Fix plugin installation error if previously a plugin was installed with the same dependency which is still pending. ([#1300](https://github.com/scm-manager/scm-manager/pull/1300))
+
 ## [2.4.0] - 2020-08-14
 ### Added
 - Introduced merge detection for receive hooks ([#1278](https://github.com/scm-manager/scm-manager/pull/1278))
diff --git a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
index 0e1e044e83..b53d715ef6 100644
--- a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
+++ b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
@@ -86,7 +86,11 @@ public class DefaultPluginManager implements PluginManager {
     if (contextFactory != null) {
       this.contextFactory = contextFactory;
     } else {
-      this.contextFactory = (availablePlugins -> PluginInstallationContext.from(getInstalled(), availablePlugins));
+      this.contextFactory = (plugins -> {
+        List<AvailablePlugin> pendingPlugins = new ArrayList<>(plugins);
+        pendingInstallQueue.stream().map(PendingPluginInstallation::getPlugin).forEach(pendingPlugins::add);
+        return PluginInstallationContext.from(getInstalled(), pendingPlugins);
+      });
     }
 
     this.computeInstallationDependencies();
diff --git a/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java b/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java
index 977451ca3a..d52bd6e51e 100644
--- a/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java
+++ b/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java
@@ -37,7 +37,6 @@ import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.api.io.TempDir;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Captor;
-import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 import sonia.scm.NotFoundException;
@@ -90,6 +89,9 @@ class DefaultPluginManagerTest {
   @Captor
   private ArgumentCaptor<PluginEvent> eventCaptor;
 
+  @Captor
+  private ArgumentCaptor<PluginInstallationContext> contextCaptor;
+
   private DefaultPluginManager manager;
 
   @Mock
@@ -624,8 +626,31 @@ class DefaultPluginManagerTest {
       assertThat(eventCaptor.getValue().getPlugin()).isEqualTo(review);
     }
 
-  }
+    @Test
+    void contextShouldContainAvailablePluginsAndPendingInstallationPlugins() {
+      DefaultPluginManager manager = new DefaultPluginManager(
+        loader, center, installer, restarter, eventBus, null
+      );
 
+      AvailablePlugin jenkins = createAvailable("scm-jenkins-plugin");
+      AvailablePlugin webhook = createAvailable("scm-webhook-plugin");
+      when(jenkins.getDescriptor().getDependencies()).thenReturn(ImmutableSet.of("scm-el-plugin"));
+      when(webhook.getDescriptor().getDependencies()).thenReturn(ImmutableSet.of("scm-el-plugin"));
+      AvailablePlugin el = createAvailable("scm-el-plugin");
+      when(center.getAvailable()).thenReturn(ImmutableSet.of(jenkins, el, webhook));
+
+      manager.install("scm-jenkins-plugin", false);
+      manager.install("scm-webhook-plugin", false);
+
+      verify(installer, times(3)).install(contextCaptor.capture(), any());
+
+      PluginInstallationContext pluginInstallationContext = contextCaptor.getAllValues().get(2);
+
+      assertThat(pluginInstallationContext.find("scm-jenkins-plugin")).isPresent();
+      assertThat(pluginInstallationContext.find("scm-webhook-plugin")).isPresent();
+      assertThat(pluginInstallationContext.find("scm-el-plugin")).isPresent();
+    }
+  }
 
   @Nested
   class WithoutReadPermissions {