diff --git a/tests/test_bootstrapper.py b/tests/test_bootstrapper.py
index 0a924eec..e640cfb0 100644
--- a/tests/test_bootstrapper.py
+++ b/tests/test_bootstrapper.py
@@ -412,7 +412,10 @@ def prepare_source_run(
 
         req = Requirement("testpkg>=1.0")
 
-        with patch.object(PrepareSource, "run", prepare_source_run):
+        with (
+            patch.object(PrepareSource, "background_work", return_value=None),
+            patch.object(PrepareSource, "run", prepare_source_run),
+        ):
             with patch.object(bt, "has_been_seen", return_value=False):
                 bt._bootstrap_one(
                     req=req,
diff --git a/tests/test_bootstrapper_iterative.py b/tests/test_bootstrapper_iterative.py
index 7852997d..d68d45d4 100644
--- a/tests/test_bootstrapper_iterative.py
+++ b/tests/test_bootstrapper_iterative.py
@@ -1247,6 +1247,7 @@ def complete_run(
         with (
             patch.object(Resolve, "run", resolve_run),
             patch.object(Start, "run", start_run),
+            patch.object(PrepareSource, "background_work", return_value=None),
             patch.object(PrepareSource, "run", prepare_source_run),
             patch.object(PrepareBuild, "run", prepare_build_run),
             patch.object(Build, "run", build_run),
@@ -1336,6 +1337,7 @@ def complete_run(
         with (
             patch.object(Resolve, "run", resolve_run),
             patch.object(Start, "run", start_run),
+            patch.object(PrepareSource, "background_work", return_value=None),
             patch.object(PrepareSource, "run", prepare_source_run),
             patch.object(Complete, "run", complete_run),
             patch.object(
@@ -1376,6 +1378,7 @@ def prepare_source_run(
             return []
 
         with (
+            patch.object(PrepareSource, "background_work", return_value=None),
             patch.object(PrepareSource, "run", prepare_source_run),
             patch.object(
                 bt._resolver,
@@ -1420,6 +1423,7 @@ def prepare_source_run(
 
         with (
             patch.object(Resolve, "run", resolve_run),
+            patch.object(PrepareSource, "background_work", return_value=None),
             patch.object(PrepareSource, "run", prepare_source_run),
             patch.object(
                 bt._resolver,
@@ -1452,6 +1456,7 @@ def prepare_source_run(
             return []
 
         with (
+            patch.object(PrepareSource, "background_work", return_value=None),
             patch.object(PrepareSource, "run", prepare_source_run),
             patch.object(
                 bt._resolver,