diff --git a/test/test_crud_v1.py b/test/test_crud_v1.py
index 3f147492a..48df16df9 100644
--- a/test/test_crud_v1.py
+++ b/test/test_crud_v1.py
@@ -122,7 +122,7 @@ def run_operation(collection, test):
                 continue
             # Requires boolean returnDocument.
             elif arg_name == "returnDocument":
-                arguments[c2s] = arguments[arg_name] == "After"
+                arguments[c2s] = arguments.pop(arg_name) == "After"
             else:
                 arguments[c2s] = arguments.pop(arg_name)
 
diff --git a/test/test_crud_v2.py b/test/test_crud_v2.py
index 9bd84d79d..9a0e735dc 100644
--- a/test/test_crud_v2.py
+++ b/test/test_crud_v2.py
@@ -93,7 +93,7 @@ class TestAllScenarios(IntegrationTest):
                         continue
                     # Requires boolean returnDocument.
                     elif arg_name == "returnDocument":
-                        arguments[c2s] = arguments[arg_name] == "After"
+                        arguments[c2s] = arguments.pop(arg_name) == "After"
                     else:
                         arguments[c2s] = arguments.pop(arg_name)
 
diff --git a/test/utils_spec_runner.py b/test/utils_spec_runner.py
index 368b87e5f..0d8fbe6c5 100644
--- a/test/utils_spec_runner.py
+++ b/test/utils_spec_runner.py
@@ -238,7 +238,7 @@ class SpecRunner(IntegrationTest):
                 continue
             # Requires boolean returnDocument.
             elif arg_name == "returnDocument":
-                arguments[c2s] = arguments[arg_name] == "After"
+                arguments[c2s] = arguments.pop(arg_name) == "After"
             elif c2s == "requests":
                 # Parse each request into a bulk write model.
                 requests = []