diff --git a/src/Maestro/SubscriptionActorService/PullRequestActor.cs b/src/Maestro/SubscriptionActorService/PullRequestActor.cs
index 3f66247936..39b0d71ac4 100644
--- a/src/Maestro/SubscriptionActorService/PullRequestActor.cs
+++ b/src/Maestro/SubscriptionActorService/PullRequestActor.cs
@@ -708,7 +708,7 @@ public async Task<ActionResult<object>> UpdateAssetsAsync(
             IRemote darcRemote = await _remoteFactory.GetRemoteAsync(targetRepository, _logger);
 
             TargetRepoDependencyUpdate repoDependencyUpdate =
-                await GetRequiredUpdates(updates, _remoteFactory, targetRepository, targetBranch);
+                await GetRequiredUpdates(updates, _remoteFactory, targetRepository, prBranch: null, targetBranch);
 
             if (repoDependencyUpdate.CoherencyCheckSuccessful && repoDependencyUpdate.RequiredUpdates.Count < 1)
             {
@@ -807,9 +807,10 @@ private async Task UpdatePullRequestAsync(InProgressPullRequest pr, List<UpdateA
             _logger.LogInformation("Updating Pull Request {url} branch {targetBranch} in {targetRepository}", pr.Url, targetBranch, targetRepository);
 
             IRemote darcRemote = await _remoteFactory.GetRemoteAsync(targetRepository, _logger);
+            PullRequest pullRequest = await darcRemote.GetPullRequestAsync(pr.Url);
 
             TargetRepoDependencyUpdate targetRepositoryUpdates =
-                await GetRequiredUpdates(updates, _remoteFactory, targetRepository, targetBranch);
+                await GetRequiredUpdates(updates, _remoteFactory, targetRepository, pullRequest.HeadBranch, targetBranch);
 
             if (targetRepositoryUpdates.CoherencyCheckSuccessful && targetRepositoryUpdates.RequiredUpdates.Count < 1)
             {
@@ -830,9 +831,6 @@ private async Task UpdatePullRequestAsync(InProgressPullRequest pr, List<UpdateA
             pr.CoherencyCheckSuccessful = targetRepositoryUpdates.CoherencyCheckSuccessful;
             pr.CoherencyErrors = targetRepositoryUpdates.CoherencyErrors;
 
-            PullRequest pullRequest = await darcRemote.GetPullRequestAsync(pr.Url);
-            string headBranch = pullRequest.HeadBranch;
-
             List<SubscriptionPullRequestUpdate> previousSubscriptions = [.. pr.ContainedSubscriptions];
 
             // Update the list of contained subscriptions with the new subscription update.
@@ -877,7 +875,7 @@ await AddDependencyFlowEventsAsync(
                 targetRepositoryUpdates.RequiredUpdates,
                 pullRequest.Description,
                 targetRepository,
-                headBranch);
+                pullRequest.HeadBranch);
 
             pullRequest.Title = await _pullRequestBuilder.GeneratePRTitleAsync(pr, targetBranch);
 
@@ -950,16 +948,17 @@ private async Task<TargetRepoDependencyUpdate> GetRequiredUpdates(
             List<UpdateAssetsParameters> updates,
             IRemoteFactory remoteFactory,
             string targetRepository,
-            string branch)
+            string? prBranch,
+            string targetBranch)
         {
-            _logger.LogInformation("Getting Required Updates from {branch} to {targetRepository}", branch, targetRepository);
+            _logger.LogInformation("Getting Required Updates for {branch} of {targetRepository}", targetBranch, targetRepository);
             // Get a remote factory for the target repo
             IRemote darc = await remoteFactory.GetRemoteAsync(targetRepository, _logger);
 
             TargetRepoDependencyUpdate repoDependencyUpdate = new();
 
             // Existing details 
-            List<DependencyDetail> existingDependencies = (await darc.GetDependenciesAsync(targetRepository, branch)).ToList();
+            List<DependencyDetail> existingDependencies = (await darc.GetDependenciesAsync(targetRepository, prBranch ?? targetBranch)).ToList();
 
             foreach (UpdateAssetsParameters update in updates)
             {
@@ -1005,13 +1004,13 @@ await UpdateSubscriptionsForMergedPRAsync(
             List<DependencyUpdate> coherencyUpdates = [];
             try
             {
-                _logger.LogInformation($"Running a coherency check on the existing dependencies for branch {branch} of repo {targetRepository}");
+                _logger.LogInformation($"Running a coherency check on the existing dependencies for branch {targetBranch} of repo {targetRepository}");
                 coherencyUpdates = await _coherencyUpdateResolver.GetRequiredCoherencyUpdatesAsync(existingDependencies, remoteFactory);
             }
             catch (DarcCoherencyException e)
             {
                 _logger.LogInformation("Failed attempting strict coherency update on branch '{strictCoherencyFailedBranch}' of repo '{strictCoherencyFailedRepo}'.",
-                     branch, targetRepository);
+                     targetBranch, targetRepository);
                 repoDependencyUpdate.CoherencyCheckSuccessful = false;
                 repoDependencyUpdate.CoherencyErrors = e.Errors.Select(e => new CoherencyErrorDetails
                 {
@@ -1031,7 +1030,7 @@ await UpdateSubscriptionsForMergedPRAsync(
                 repoDependencyUpdate.RequiredUpdates.Add((coherencyUpdateParameters, coherencyUpdates.ToList()));
             }
 
-            _logger.LogInformation("Finished getting Required Updates from {branch} to {targetRepository}", branch, targetRepository);
+            _logger.LogInformation("Finished getting Required Updates for {branch} of {targetRepository}", targetBranch, targetRepository);
             return repoDependencyUpdate;
         }
 
diff --git a/test/SubscriptionActorService.Tests/PendingUpdatesTests.cs b/test/SubscriptionActorService.Tests/PendingUpdatesTests.cs
index 4476d28d21..dfc3854f51 100644
--- a/test/SubscriptionActorService.Tests/PendingUpdatesTests.cs
+++ b/test/SubscriptionActorService.Tests/PendingUpdatesTests.cs
@@ -69,7 +69,7 @@ public async Task PendingUpdatesUpdatablePr()
             await WhenProcessPendingUpdatesAsyncIsCalled();
             ThenUpdateReminderIsRemoved();
             AndPendingUpdateIsRemoved();
-            ThenGetRequiredUpdatesShouldHaveBeenCalled(b);
+            ThenGetRequiredUpdatesShouldHaveBeenCalled(b, true);
             AndCommitUpdatesShouldHaveBeenCalled(b);
             AndUpdatePullRequestShouldHaveBeenCalled();
             AndShouldHavePullRequestCheckReminder();
diff --git a/test/SubscriptionActorService.Tests/PullRequestActorTests.cs b/test/SubscriptionActorService.Tests/PullRequestActorTests.cs
index 917814843c..0f1bad393c 100644
--- a/test/SubscriptionActorService.Tests/PullRequestActorTests.cs
+++ b/test/SubscriptionActorService.Tests/PullRequestActorTests.cs
@@ -122,14 +122,14 @@ protected void GivenAPullRequestCheckReminder()
         Reminders.Data[PullRequestActorImplementation.PullRequestCheckKey] = reminder;
     }
 
-    protected void ThenGetRequiredUpdatesShouldHaveBeenCalled(Build withBuild)
+    protected void ThenGetRequiredUpdatesShouldHaveBeenCalled(Build withBuild, bool prExists)
     {
         var assets = new List<IEnumerable<AssetData>>();
         var dependencies = new List<IEnumerable<DependencyDetail>>();
         _updateResolver
             .Verify(r => r.GetRequiredNonCoherencyUpdates(SourceRepo, NewCommit, Capture.In(assets), Capture.In(dependencies)));
         _darcRemotes[TargetRepo]
-            .Verify(r => r.GetDependenciesAsync(TargetRepo, TargetBranch, null));
+            .Verify(r => r.GetDependenciesAsync(TargetRepo, prExists ? InProgressPrHeadBranch : TargetBranch, null));
         _updateResolver
             .Verify(r => r.GetRequiredCoherencyUpdatesAsync(Capture.In(dependencies), _remoteFactory.Object));
         assets.Should()
diff --git a/test/SubscriptionActorService.Tests/UpdateAssetsTests.cs b/test/SubscriptionActorService.Tests/UpdateAssetsTests.cs
index 747d3892a3..c00d810efe 100644
--- a/test/SubscriptionActorService.Tests/UpdateAssetsTests.cs
+++ b/test/SubscriptionActorService.Tests/UpdateAssetsTests.cs
@@ -34,7 +34,7 @@ public async Task UpdateWithAssetsNoExistingPR(bool batchable)
 
         await WhenUpdateAssetsAsyncIsCalled(b);
 
-        ThenGetRequiredUpdatesShouldHaveBeenCalled(b);
+        ThenGetRequiredUpdatesShouldHaveBeenCalled(b, false);
         AndCreateNewBranchShouldHaveBeenCalled();
         AndCommitUpdatesShouldHaveBeenCalled(b);
         AndCreatePullRequestShouldHaveBeenCalled();
@@ -62,7 +62,7 @@ public async Task UpdateWithAssetsExistingPR(bool batchable)
         using (WithExistingPullRequest(SynchronizePullRequestResult.InProgressCanUpdate))
         {
             await WhenUpdateAssetsAsyncIsCalled(b);
-            ThenGetRequiredUpdatesShouldHaveBeenCalled(b);
+            ThenGetRequiredUpdatesShouldHaveBeenCalled(b, true);
             AndCommitUpdatesShouldHaveBeenCalled(b);
             AndUpdatePullRequestShouldHaveBeenCalled();
             AndShouldHavePullRequestCheckReminder();
@@ -110,7 +110,7 @@ public async Task UpdateWithNoAssets(bool batchable)
 
         await WhenUpdateAssetsAsyncIsCalled(b);
 
-        ThenGetRequiredUpdatesShouldHaveBeenCalled(b);
+        ThenGetRequiredUpdatesShouldHaveBeenCalled(b, false);
         AndSubscriptionShouldBeUpdatedForMergedPullRequest(b);
     }
 
@@ -134,7 +134,7 @@ public async Task UpdateWithAssetsWhenStrictAlgorithmFails(bool batchable)
 
         await WhenUpdateAssetsAsyncIsCalled(b);
 
-        ThenGetRequiredUpdatesShouldHaveBeenCalled(b);
+        ThenGetRequiredUpdatesShouldHaveBeenCalled(b, false);
         AndCreateNewBranchShouldHaveBeenCalled();
         AndCommitUpdatesShouldHaveBeenCalled(b);
         AndCreatePullRequestShouldHaveBeenCalled();