diff --git a/sonar-project.properties b/sonar-project.properties
index d48f9459..6815bc5f 100644
--- a/sonar-project.properties
+++ b/sonar-project.properties
@@ -1,4 +1,6 @@
 sonar.projectKey=Open-MBEE_flexo-mms-layer1-service
 sonar.organization=openmbee
 sonar.language=kotlin
-sonar.coverage.jacoco.xmlReportPaths=build/reports/jacoco/test/jacocoTestReport.xml
\ No newline at end of file
+sonar.coverage.jacoco.xmlReportPaths=build/reports/jacoco/test/jacocoTestReport.xml
+sonar.sources=src/main/
+sonar.tests=src/test/
\ No newline at end of file
diff --git a/src/main/kotlin/org/openmbee/flexo/mms/routes/gsp/ModelLoad.kt b/src/main/kotlin/org/openmbee/flexo/mms/routes/gsp/ModelLoad.kt
index 92607978..a496ea97 100644
--- a/src/main/kotlin/org/openmbee/flexo/mms/routes/gsp/ModelLoad.kt
+++ b/src/main/kotlin/org/openmbee/flexo/mms/routes/gsp/ModelLoad.kt
@@ -217,29 +217,53 @@ fun Route.loadModel() {
 
             // compute the delta
             run {
-                val updateString = genDiffUpdate("", localConditions, """
-                    graph mor-graph:Metadata {
-                        # select the latest commit from the current named ref
-                        ?srcRef mms:commit ?srcCommit .
-                        
-                        # get the latest snapshot associated with the source commit
-                        ?srcCommit ^mms:commit/mms:snapshot ?srcSnapshot .
-                        {
-                            # prefer the model snapshot
-                            ?srcSnapshot a mms:Model ;
-                                mms:graph ?srcGraph  .
-                        } union {
-                            # settle for staging...
-                            ?srcSnapshot a mms:Staging ;
-                                mms:graph ?srcGraph .
+                val selectQueryString = """
+                    select distinct ?srcGraph ?srcCommit {
+                        graph mor-graph:Metadata {
+                            # select the latest commit from the current named ref
+                            ?srcRef mms:commit ?srcCommit .
                             
-                            # ...if model is not available
-                            filter not exists {
-                                ?srcCommit ^mms:commit/mms:snapshot/a mms:Model .
+                            # get the latest snapshot associated with the source commit
+                            ?srcCommit ^mms:commit/mms:snapshot ?srcSnapshot .
+                            {
+                                # prefer the model snapshot
+                                ?srcSnapshot a mms:Model ;
+                                    mms:graph ?srcGraph  .
+                            } union {
+                                # settle for staging...
+                                ?srcSnapshot a mms:Staging ;
+                                    mms:graph ?srcGraph .
+                                
+                                # ...if model is not available
+                                filter not exists {
+                                    ?srcCommit ^mms:commit/mms:snapshot/a mms:Model .
+                                }
                             }
                         }
                     }
-                """)
+                """.trimIndent()
+
+                val selectResponseText = executeSparqlSelectOrAsk(selectQueryString) {
+                    prefixes(prefixes)
+
+                    iri(
+                        // use current branch as ref source
+                        "srcRef" to prefixes["morb"]!!,
+                    )
+                }
+
+                // parse the JSON response
+                val bindings = Json.parseToJsonElement(selectResponseText).jsonObject["results"]!!.jsonObject["bindings"]!!.jsonArray
+
+                if(bindings.size != 1) {
+                    throw ServerBugException("Failed to resolve source graph")
+                }
+
+                val sourceGraphIri = bindings[0].jsonObject["srcGraph"]!!.jsonObject["value"]!!.jsonPrimitive.content
+
+                val sourceCommitri = bindings[0].jsonObject["srcCommit"]!!.jsonObject["value"]!!.jsonPrimitive.content
+
+                val updateString = genDiffUpdate("", localConditions, "")
 
                 executeSparqlUpdate(updateString) {
                     prefixes(prefixes)
@@ -253,6 +277,12 @@ fun Route.loadModel() {
 
                         // set dst commit (this commit)
                         "dstCommit" to prefixes["morc"]!!,
+
+                        // use explicit srcGraph
+                        "srcGraph" to sourceGraphIri,
+
+                        // use explicit srcCommit
+                        "srcCommit" to sourceCommitri,
                     )
                 }
             }