diff --git a/Scalar.Service/RepoRegistry.cs b/Scalar.Service/RepoRegistry.cs
index ac21f8c905..8461f78236 100644
--- a/Scalar.Service/RepoRegistry.cs
+++ b/Scalar.Service/RepoRegistry.cs
@@ -174,22 +174,59 @@ public void RunMaintenanceTaskForRepos(MaintenanceTasks.Task task, string userId
             }
             else
             {
-                metadata.Add(TracingConstants.MessageKey.InfoMessage, "Calling maintenance verb");
+                string rootPath;
+                string errorMessage;
 
                 foreach (RepoRegistration repo in activeRepos)
                 {
+                    rootPath = Path.GetPathRoot(repo.EnlistmentRoot);
+
                     metadata[nameof(repo.EnlistmentRoot)] = repo.EnlistmentRoot;
                     metadata[nameof(task)] = task;
-                    this.tracer.RelatedEvent(
-                        EventLevel.Informational,
-                        $"{nameof(this.RunMaintenanceTaskForRepos)}_CallingMaintenance",
-                        metadata);
+                    metadata[nameof(rootPath)] = rootPath;
+                    metadata.Remove(nameof(errorMessage));
 
-                    if (!this.scalarVerb.CallMaintenance(task, repo.EnlistmentRoot, sessionId))
+                    if (!string.IsNullOrWhiteSpace(rootPath) && !this.fileSystem.DirectoryExists(rootPath))
                     {
-                        // TODO: #111 - If the maintenance verb failed because the repo is no longer
-                        // on disk, it should be removed from the registry
+                        // If the volume does not exist we'll assume the drive was removed or is encrypted,
+                        // and we'll leave the repo in the registry (but we won't run maintenance on it).
+                        this.tracer.RelatedEvent(
+                            EventLevel.Informational,
+                            $"{nameof(this.RunMaintenanceTaskForRepos)}_SkippedRepoWithMissingVolume",
+                            metadata);
+
+                        continue;
                     }
+
+                    if (!this.fileSystem.DirectoryExists(repo.EnlistmentRoot))
+                    {
+                        // The repo is no longer on disk (but its volume is present)
+                        // Unregister the repo
+                        if (this.TryRemoveRepo(repo.EnlistmentRoot, out errorMessage))
+                        {
+                            this.tracer.RelatedEvent(
+                                EventLevel.Informational,
+                                $"{nameof(this.RunMaintenanceTaskForRepos)}_RemovedMissingRepo",
+                                metadata);
+                        }
+                        else
+                        {
+                            metadata[nameof(errorMessage)] = errorMessage;
+                            this.tracer.RelatedEvent(
+                                EventLevel.Informational,
+                                $"{nameof(this.RunMaintenanceTaskForRepos)}_FailedToRemoveRepo",
+                                metadata);
+                        }
+
+                        continue;
+                    }
+
+                    this.tracer.RelatedEvent(
+                                EventLevel.Informational,
+                                $"{nameof(this.RunMaintenanceTaskForRepos)}_CallingMaintenance",
+                                metadata);
+
+                    this.scalarVerb.CallMaintenance(task, repo.EnlistmentRoot, sessionId);
                 }
             }
         }
diff --git a/Scalar.UnitTests/Service/Mac/MacServiceTests.cs b/Scalar.UnitTests/Service/Mac/MacServiceTests.cs
index 22fb996414..cebad8993f 100644
--- a/Scalar.UnitTests/Service/Mac/MacServiceTests.cs
+++ b/Scalar.UnitTests/Service/Mac/MacServiceTests.cs
@@ -3,6 +3,7 @@
 using Scalar.Common;
 using Scalar.Common.Maintenance;
 using Scalar.Service;
+using Scalar.Tests.Should;
 using Scalar.UnitTests.Mock.Common;
 using Scalar.UnitTests.Mock.FileSystem;
 using System.IO;
@@ -30,11 +31,35 @@ public void SetUp()
             this.scalarPlatform.MockCurrentUser = ExpectedActiveUserId.ToString();
         }
 
+        [TestCase]
+        public void RepoRegistryRemovesRegisteredRepoIfMissingFromDisk()
+        {
+            Mock<IScalarVerbRunner> repoMounterMock = new Mock<IScalarVerbRunner>(MockBehavior.Strict);
+
+            this.fileSystem.DirectoryExists(ExpectedActiveRepoPath).ShouldBeFalse($"{ExpectedActiveRepoPath} should not exist");
+
+            MaintenanceTasks.Task task = MaintenanceTasks.Task.FetchCommitsAndTrees;
+
+            this.CreateTestRepos(ServiceDataLocation);
+            RepoRegistry repoRegistry = new RepoRegistry(
+                this.tracer,
+                this.fileSystem,
+                ServiceDataLocation,
+                repoMounterMock.Object);
+
+            repoRegistry.RunMaintenanceTaskForRepos(task, ExpectedActiveUserId.ToString(), ExpectedSessionId);
+            repoMounterMock.VerifyAll();
+
+            repoRegistry.ReadRegistry().ShouldNotContain(entry => entry.Key.Equals(ExpectedActiveRepoPath));
+        }
+
         [TestCase]
         public void RepoRegistryCallsMaintenanceVerbOnlyForRegisteredRepos()
         {
             Mock<IScalarVerbRunner> repoMounterMock = new Mock<IScalarVerbRunner>(MockBehavior.Strict);
 
+            this.fileSystem.CreateDirectory(ExpectedActiveRepoPath);
+
             MaintenanceTasks.Task task = MaintenanceTasks.Task.FetchCommitsAndTrees;
             repoMounterMock.Setup(mp => mp.CallMaintenance(task, ExpectedActiveRepoPath, ExpectedActiveUserId)).Returns(true);