diff --git a/src/pdl/pdl_context.py b/src/pdl/pdl_context.py
index 26909d109..1d1bac708 100644
--- a/src/pdl/pdl_context.py
+++ b/src/pdl/pdl_context.py
@@ -179,4 +179,4 @@ def add_done_callback(
         case IndependentContext(context=c):
             p.context = PdlApply(f, c)
         case _:
-            assert False
+            assert False, f"Unexpected context type {type(p)}: {p}"
diff --git a/src/pdl/pdl_interpreter.py b/src/pdl/pdl_interpreter.py
index 57f56f153..d890b5cdd 100644
--- a/src/pdl/pdl_interpreter.py
+++ b/src/pdl/pdl_interpreter.py
@@ -2146,16 +2146,18 @@ def process_call_code(
         case "ipython":
             try:
                 result = call_ipython(code_s, scope)
-                background = PdlList(
-                    [
-                        PdlDict(  # type: ignore
-                            {
-                                "role": state.role,
-                                "content": lazy_apply(str, result),
-                                "pdl__defsite": block.pdl__id,
-                            },
-                        ),
-                    ],  # type: ignore
+                background = SingletonContext(
+                    PdlList(
+                        [
+                            PdlDict(  # type: ignore
+                                {
+                                    "role": state.role,
+                                    "content": lazy_apply(str, result),
+                                    "pdl__defsite": block.pdl__id,
+                                },
+                            ),
+                        ],  # type: ignore
+                    )
                 )
             except KeyboardInterrupt as exc:
                 raise exc from exc