diff --git a/patterns/other/graph_search.py b/patterns/other/graph_search.py
index e3c92140..b4d19f00 100644
--- a/patterns/other/graph_search.py
+++ b/patterns/other/graph_search.py
@@ -78,7 +78,7 @@ def find_shortest_path_bfs(self, start: str, end: str) -> list[str] | None:
 
         while len(queue):
             value = queue.pop(0)
-            for node in self.graph[value]:
+            for node in self.graph.get(value, []):
                 if node not in dist_to.keys():
                     edge_to[node] = value
                     dist_to[node] = dist_to[value] + 1
diff --git a/tests/test_graph_search.py b/tests/test_graph_search.py
new file mode 100644
index 00000000..dcbdce1a
--- /dev/null
+++ b/tests/test_graph_search.py
@@ -0,0 +1,16 @@
+from patterns.other.graph_search import GraphSearch
+
+
+def test_find_shortest_path_bfs_handles_leaf_nodes_without_outgoing_edges():
+    # Leaf nodes ('C', 'D') have no entry in the graph dict, same as a
+    # real-world adjacency list that only lists nodes with outgoing edges.
+    graph = {
+        "A": ["B"],
+        "B": ["C", "D"],
+    }
+    search = GraphSearch(graph)
+
+    assert search.find_shortest_path_bfs("A", "D") == ["A", "B", "D"]
+    # Searching for a node that is unreachable must still traverse through
+    # the leaf nodes without raising KeyError.
+    assert search.find_shortest_path_bfs("A", "Z") is None