diff --git a/src/library_analyzer/processing/api/purity_analysis/_build_call_graph.py b/src/library_analyzer/processing/api/purity_analysis/_build_call_graph.py
index 949263ea..d521c267 100644
--- a/src/library_analyzer/processing/api/purity_analysis/_build_call_graph.py
+++ b/src/library_analyzer/processing/api/purity_analysis/_build_call_graph.py
@@ -218,12 +218,12 @@ def _handle_unknown_call(self, call: Symbol, reason: Reasons) -> None:
         # Deal with the case that the call calls a function parameter.
         elif isinstance(call, Parameter):
             self.call_graph_forest.get_graph(reason.id).reasons.unknown_calls[call.id] = UnknownProto(
-                symbol=call, origin=reason.function_scope.symbol,
+                symbol=call, origin=reason.function_scope.symbol if reason.function_scope else None,
             )
 
         else:
             self.call_graph_forest.get_graph(reason.id).reasons.unknown_calls[call.id] = UnknownProto(
-                symbol=call, origin=reason.function_scope.symbol,
+                symbol=call, origin=reason.function_scope.symbol if reason.function_scope else None,
             )
 
     def _handle_cycles(self, removed_nodes: set[NodeID] | None = None) -> None:
diff --git a/src/library_analyzer/processing/api/purity_analysis/_resolve_references.py b/src/library_analyzer/processing/api/purity_analysis/_resolve_references.py
index a4c76d37..2a49efe4 100644
--- a/src/library_analyzer/processing/api/purity_analysis/_resolve_references.py
+++ b/src/library_analyzer/processing/api/purity_analysis/_resolve_references.py
@@ -476,7 +476,7 @@ def _find_value_references(
                     import_def,
                     inferred_node=inferred_node_def,  # type: ignore[type-var] # import def is not None.
                 )
-                specified_import_def.id.name = specified_import_def.id.name + "." + specified_import_def.name
+                specified_import_def.id.name = specified_import_def.id.name + "." + specified_import_def.name  # type: ignore[union-attr] # specified_import_def is not None.
 
                 if specified_import_def:
                     result_value_reference.referenced_symbols.append(specified_import_def)
diff --git a/src/library_analyzer/processing/api/purity_analysis/model/_purity.py b/src/library_analyzer/processing/api/purity_analysis/model/_purity.py
index 401b747f..711a460f 100644
--- a/src/library_analyzer/processing/api/purity_analysis/model/_purity.py
+++ b/src/library_analyzer/processing/api/purity_analysis/model/_purity.py
@@ -203,7 +203,7 @@ def to_dict(self, shorten: bool = False) -> dict[str, Any]:
                     case _:
                         raise TypeError(f"Unknown reason type: {reason}")
         if not shorten:
-            combined_reasons = {
+            combined_reasons: dict[str, Any] = {
                 "NonLocalVariableRead": non_local_variable_reads,
                 "NonLocalVariableWrite": non_local_variable_writes,
                 "FileRead": file_reads,
diff --git a/src/library_analyzer/processing/api/purity_analysis/model/_reference.py b/src/library_analyzer/processing/api/purity_analysis/model/_reference.py
index d93d66d2..fd2ebcdc 100644
--- a/src/library_analyzer/processing/api/purity_analysis/model/_reference.py
+++ b/src/library_analyzer/processing/api/purity_analysis/model/_reference.py
@@ -186,9 +186,6 @@ def join_reasons_list(self, reasons_list: list[Reasons]) -> Reasons:
             result.join_reasons(reason)
         return result
 
-    def __iter__(self) -> Iterator[Symbol]:
-        return iter(self.writes_to.union(self.reads_from).union(self.calls))
-
     def join_reasons(self, other: Reasons) -> Reasons:
         """Join two Reasons objects.
 
diff --git a/tests/library_analyzer/processing/api/purity_analysis/test_resolve_references.py b/tests/library_analyzer/processing/api/purity_analysis/test_resolve_references.py
index 38dd1a1b..d530aec6 100644
--- a/tests/library_analyzer/processing/api/purity_analysis/test_resolve_references.py
+++ b/tests/library_analyzer/processing/api/purity_analysis/test_resolve_references.py
@@ -251,7 +251,7 @@ def transform_reasons(reasons: dict[NodeID, Reasons]) -> dict[str, SimpleReasons
                             else (
                                 f"{target_reference.symbol.__class__.__name__}.{target_reference.symbol.klass.name}.{target_reference.symbol.node.member}.line{target_reference.symbol.node.node.fromlineno}"  # type: ignore[union-attr] # "None" has no attribute "name" but since we check for the type before, this is fine
                                 if isinstance(target_reference.symbol, InstanceVariable)
-                                else f"{target_reference.symbol.__class__.__name__}.{target_reference.symbol.node.name}.line{target_reference.symbol.node.fromlineno}"
+                                else f"{target_reference.symbol.__class__.__name__}.{target_reference.symbol.node.name}.line{target_reference.symbol.node.fromlineno}"  # type: ignore[union-attr] # "None" has no attribute "name" but since we check for the type before, this is fine
                             )
                         )
                         for target_reference in function_references.writes_to.values()
@@ -263,7 +263,7 @@ def transform_reasons(reasons: dict[NodeID, Reasons]) -> dict[str, SimpleReasons
                             else (
                                 f"{value_reference.symbol.__class__.__name__}.{value_reference.symbol.klass.name}.{value_reference.symbol.node.member}.line{value_reference.symbol.node.node.fromlineno}"  # type: ignore[union-attr] # "None" has no attribute "name" but since we check for the type before, this is fine
                                 if isinstance(value_reference.symbol, InstanceVariable)
-                                else f"{value_reference.symbol.__class__.__name__}.{value_reference.symbol.node.name}.line{value_reference.symbol.node.fromlineno}"
+                                else f"{value_reference.symbol.__class__.__name__}.{value_reference.symbol.node.name}.line{value_reference.symbol.node.fromlineno}"  # type: ignore[union-attr] # "None" has no attribute "name" but since we check for the type before, this is fine
                             )
                         )
                         for value_reference in function_references.reads_from.values()