diff --git a/ast/src/lang/graphs/graph_ops.rs b/ast/src/lang/graphs/graph_ops.rs
index 594be5f2a..033cd7e74 100644
--- a/ast/src/lang/graphs/graph_ops.rs
+++ b/ast/src/lang/graphs/graph_ops.rs
@@ -142,6 +142,15 @@ impl GraphOps {
 
                 let muted_nodes = self.collect_muted_nodes_for_files(&absolute_files).await?;
 
+                let root_prefix = format!("{}/", graph_root);
+                let caller_files: Vec<String> = self
+                    .graph
+                    .get_incoming_edge_source_files(&absolute_files)
+                    .await?
+                    .iter()
+                    .filter_map(|f| f.strip_prefix(&root_prefix).map(str::to_string))
+                    .collect();
+
                 info!(
                     "[incremental] removing existing nodes for {} modified file(s)",
                     modified_files.len()
@@ -156,10 +165,19 @@ impl GraphOps {
                     modified_files.len()
                 );
 
+                let mut parse_files = modified_files;
+                if !caller_files.is_empty() {
+                    info!(
+                        "[incremental] re-parsing {} caller file(s) with edges into modified files",
+                        caller_files.len()
+                    );
+                    parse_files.extend(caller_files);
+                }
+
                 let mut subgraph_repos = Repo::new_multi_detect(
                     &repo_path,
                     Some(repo_url.to_string()),
-                    modified_files,
+                    parse_files,
                     vec![stored_hash.to_string(), current_hash.to_string()],
                     use_lsp,
                 )
diff --git a/ast/src/lang/graphs/neo4j/operations/migration.rs b/ast/src/lang/graphs/neo4j/operations/migration.rs
index 1003819b4..595bea5c0 100644
--- a/ast/src/lang/graphs/neo4j/operations/migration.rs
+++ b/ast/src/lang/graphs/neo4j/operations/migration.rs
@@ -159,6 +159,29 @@ impl Neo4jGraph {
         Ok(incoming)
     }
 
+    pub async fn get_incoming_edge_source_files(
+        &self,
+        file_paths: &[String],
+    ) -> Result<Vec<String>> {
+        if file_paths.is_empty() {
+            return Ok(Vec::new());
+        }
+        let connection = self.ensure_connected().await?;
+        let (query_str, params) = incoming_edge_source_files_query(file_paths);
+        let mut query_obj = query(&query_str);
+        for (key, value) in params.value.iter() {
+            query_obj = query_obj.param(key.value.as_str(), value.clone());
+        }
+        let mut result = connection.execute(query_obj).await?;
+        let mut files = Vec::new();
+        while let Some(row) = result.next().await? {
+            if let Ok(file) = row.get::<String>("file") {
+                files.push(file);
+            }
+        }
+        Ok(files)
+    }
+
     pub async fn clear_existing_graph(&self, root: &str) -> Result<()> {
         let connection = self.ensure_connected().await?;
         info!("Clearing existing graph for root: {}", root);
@@ -316,6 +339,23 @@ pub fn get_repository_hash_query(repo_url: &str) -> (String, BoltMap) {
     (query.to_string(), params)
 }
 
+pub fn incoming_edge_source_files_query(file_paths: &[String]) -> (String, BoltMap) {
+    let mut params = BoltMap::new();
+    let files: Vec<neo4rs::BoltType> = file_paths
+        .iter()
+        .map(|p| neo4rs::BoltType::String(p.clone().into()))
+        .collect();
+    boltmap_insert_list(&mut params, "files", files);
+
+    let query = "
+        MATCH (src:Data_Bank)-[r]->(dst:Data_Bank)
+        WHERE dst.file IN $files AND NOT src.file IN $files AND type(r) <> 'CONTAINS'
+        RETURN DISTINCT src.file as file
+    ";
+
+    (query.to_string(), params)
+}
+
 /// Single-statement detach-delete. Kept for callers that explicitly want the
 /// all-in-one-transaction semantics; the incremental sync path prefers the
 /// chunked variant below to avoid massive lock sets.
diff --git a/standalone/tests/cross_repo_sync.rs b/standalone/tests/cross_repo_sync.rs
index b5732c022..598a0735a 100644
--- a/standalone/tests/cross_repo_sync.rs
+++ b/standalone/tests/cross_repo_sync.rs
@@ -99,6 +99,38 @@ fn linked_requests(g: &mut GraphOps) -> BTreeSet<String> {
         .collect()
 }
 
+fn function_calls(g: &mut GraphOps) -> BTreeSet<String> {
+    g.graph
+        .find_nodes_with_edge_type(NodeType::Function, NodeType::Function, EdgeType::Calls)
+        .iter()
+        .map(|(src, dst)| format!("{} -> {}", src.name, dst.name))
+        .collect()
+}
+
+fn integration_test_calls(g: &mut GraphOps) -> BTreeSet<String> {
+    g.graph
+        .find_nodes_with_edge_type(
+            NodeType::IntegrationTest,
+            NodeType::Function,
+            EdgeType::Calls,
+        )
+        .iter()
+        .map(|(src, dst)| format!("{} -> {}", src.name, dst.name))
+        .collect()
+}
+
+fn integration_test_endpoint_calls(g: &mut GraphOps) -> BTreeSet<String> {
+    g.graph
+        .find_nodes_with_edge_type(
+            NodeType::IntegrationTest,
+            NodeType::Endpoint,
+            EdgeType::Calls,
+        )
+        .iter()
+        .map(|(src, dst)| format!("{} -> {}", src.name, dst.name))
+        .collect()
+}
+
 fn expected(items: &[&str]) -> BTreeSet<String> {
     items.iter().map(|s| s.to_string()).collect()
 }
@@ -123,6 +155,70 @@ fn baseline_edges() -> BTreeSet<String> {
     ])
 }
 
+fn baseline_function_calls() -> BTreeSet<String> {
+    expected(&[
+        "main -> NewRouter",
+        "Login -> writeJSON",
+        "ListBounties -> AllBounties",
+        "ListBounties -> writeJSON",
+        "CreateBounty -> SaveBounty",
+        "CreateBounty -> writeJSON",
+        "GetBounty -> FindBounty",
+        "GetBounty -> writeJSON",
+        "UpdateBounty -> SaveBounty",
+        "UpdateBounty -> writeJSON",
+        "DeleteBounty -> RemoveBounty",
+        "ListPeople -> AllPeople",
+        "ListPeople -> writeJSON",
+        "GetPerson -> FindPerson",
+        "GetPerson -> writeJSON",
+        "GetWorkspace -> writeJSON",
+    ])
+}
+
+fn evolved_function_calls() -> BTreeSet<String> {
+    expected(&[
+        "main -> NewRouter",
+        "Login -> writeJSON",
+        "ListBounties -> AllBounties",
+        "ListBounties -> writeJSON",
+        "CreateBounty -> SaveBounty",
+        "CreateBounty -> writeJSON",
+        "GetBounty -> FindBounty",
+        "GetBounty -> writeJSON",
+        "UpdateBounty -> SaveBounty",
+        "UpdateBounty -> writeJSON",
+        "AssignBounty -> FindBounty",
+        "AssignBounty -> SaveBounty",
+        "AssignBounty -> writeJSON",
+        "ListUsers -> AllPeople",
+        "ListUsers -> writeJSON",
+        "GetUser -> FindPerson",
+        "GetUser -> writeJSON",
+        "GetWorkspace -> writeJSON",
+        "ListWorkspaceBounties -> AllBounties",
+        "ListWorkspaceBounties -> writeJSON",
+    ])
+}
+
+fn expected_test_calls() -> BTreeSet<String> {
+    expected(&[
+        "TestListBounties -> ListBounties",
+        "TestLoginRejectsBadBody -> Login",
+    ])
+}
+
+fn expected_test_endpoint_calls() -> BTreeSet<String> {
+    expected(&[
+        "TestListBounties -> /bounties",
+        "TestLoginRejectsBadBody -> /auth/login",
+    ])
+}
+
+fn unmodified_caller_probes() -> [&'static str; 2] {
+    ["main -> NewRouter", "Login -> writeJSON"]
+}
+
 fn evolved_edges() -> BTreeSet<String> {
     expected(&[
         "GET /bounties",
@@ -208,6 +304,116 @@ async fn test_backward_sync_full_reindex() {
     );
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_sync_preserves_calls_from_unmodified_files() {
+    let state = test_state();
+    let mut g = fresh_graph().await;
+
+    reset_clones();
+    let _ = ingest(State(state.clone()), Json(body(BE, Some("before"))))
+        .await
+        .expect("backend ingest failed");
+
+    let baseline = function_calls(&mut g);
+    for probe in unmodified_caller_probes() {
+        assert!(
+            baseline.contains(probe),
+            "baseline missing call edge {probe}; full set: {baseline:?}"
+        );
+    }
+    assert_eq!(
+        baseline,
+        baseline_function_calls(),
+        "baseline function call graph"
+    );
+    assert_eq!(
+        integration_test_calls(&mut g),
+        expected_test_calls(),
+        "baseline test-to-function call edges"
+    );
+    assert_eq!(
+        integration_test_endpoint_calls(&mut g),
+        expected_test_endpoint_calls(),
+        "baseline test-to-endpoint call edges"
+    );
+    let baseline_pairs = g.graph.find_nodes_with_edge_type(
+        NodeType::Function,
+        NodeType::Function,
+        EdgeType::Calls,
+    );
+    assert_eq!(
+        baseline_pairs.len(),
+        baseline.len(),
+        "duplicate baseline function call edges"
+    );
+
+    let auth_file = "fayekelmith/graph-update-backend/handlers/auth.go";
+    let muted = g
+        .set_node_muted(&NodeType::Function, "Login", auth_file, true)
+        .await
+        .unwrap_or(0);
+    assert!(muted > 0, "expected to mute the Login function node");
+
+    sync_repo(&state, BE, "after").await;
+
+    let evolved = function_calls(&mut g);
+    for probe in unmodified_caller_probes() {
+        assert!(
+            evolved.contains(probe),
+            "call edge from unmodified file lost after sync: {probe}"
+        );
+    }
+    assert!(
+        !evolved.contains("DeleteBounty -> RemoveBounty"),
+        "call edge from deleted function survived sync"
+    );
+    assert!(
+        !evolved.contains("ListPeople -> AllPeople"),
+        "call edge from renamed-away function survived sync"
+    );
+    assert_eq!(
+        evolved,
+        evolved_function_calls(),
+        "evolved function call graph"
+    );
+    assert_eq!(
+        integration_test_calls(&mut g),
+        expected_test_calls(),
+        "test-to-function call edges from unmodified test file lost after sync"
+    );
+    assert_eq!(
+        integration_test_endpoint_calls(&mut g),
+        expected_test_endpoint_calls(),
+        "test-to-endpoint call edges from unmodified test file lost after sync"
+    );
+    let evolved_pairs = g.graph.find_nodes_with_edge_type(
+        NodeType::Function,
+        NodeType::Function,
+        EdgeType::Calls,
+    );
+    assert_eq!(
+        evolved_pairs.len(),
+        evolved.len(),
+        "duplicate function call edges after sync"
+    );
+    let test_pairs = g.graph.find_nodes_with_edge_type(
+        NodeType::IntegrationTest,
+        NodeType::Function,
+        EdgeType::Calls,
+    );
+    assert_eq!(
+        test_pairs.len(),
+        expected_test_calls().len(),
+        "duplicate test call edges after sync"
+    );
+    assert!(
+        g.is_node_muted(&NodeType::Function, "Login", auth_file)
+            .await
+            .unwrap_or(false),
+        "mute on re-parsed caller file lost after sync"
+    );
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_cross_repo_muted_preservation() {
     let state = test_state();