diff --git a/gfe_integration_tests/sdram_edge_tests/test_multi_dest_internal/sdram_splitter.py b/gfe_integration_tests/sdram_edge_tests/test_multi_dest_internal/sdram_splitter.py
index 61180fb3..a866a3d8 100644
--- a/gfe_integration_tests/sdram_edge_tests/test_multi_dest_internal/sdram_splitter.py
+++ b/gfe_integration_tests/sdram_edge_tests/test_multi_dest_internal/sdram_splitter.py
@@ -101,7 +101,7 @@ def get_in_coming_slices(self) -> List[Slice]:
 
     @overrides(AbstractSplitterCommon.machine_vertices_for_recording)
     def machine_vertices_for_recording(
-            self, variable_to_record) -> List[SDRAMMachineVertex]:
+            self, variable_to_record: str) -> List[SDRAMMachineVertex]:
         return [self._pre_vertex].extend(self._post_vertices)
 
     @overrides(AbstractSplitterCommon.reset_called)
diff --git a/gfe_integration_tests/sdram_edge_tests/test_multi_src_internal/sdram_splitter.py b/gfe_integration_tests/sdram_edge_tests/test_multi_src_internal/sdram_splitter.py
index ebf92f0e..85947749 100644
--- a/gfe_integration_tests/sdram_edge_tests/test_multi_src_internal/sdram_splitter.py
+++ b/gfe_integration_tests/sdram_edge_tests/test_multi_src_internal/sdram_splitter.py
@@ -96,7 +96,7 @@ def get_in_coming_slices(self) -> List[Slice]:
 
     @overrides(AbstractSplitterCommon.machine_vertices_for_recording)
     def machine_vertices_for_recording(
-            self, variable_to_record) -> List[SourceSegmentedSDRAMMachinePartition]:
+            self, variable_to_record: str) -> List[SourceSegmentedSDRAMMachinePartition]:
         return [self._post_vertex].extend(self._pre_vertices)
 
     @overrides(AbstractSplitterCommon.reset_called)