diff --git a/requirements.dev.txt b/requirements.dev.txt
index 3f28dd47..2e19cf75 100644
--- a/requirements.dev.txt
+++ b/requirements.dev.txt
@@ -7,4 +7,4 @@ tox==3.15.1
 coveralls==2.0.0
 twine==3.1.1
 wheel==0.34.2
-git+git://github.com/ChrisTimperley/roswire.git@e69dc7949ca456829d0b5da1caa39d1be7085aa7
+git+git://github.com/ChrisTimperley/roswire.git@db2bcac0f903313dc22d7a5b919fe99c4a2c53f5
diff --git a/src/rosdiscover/cli.py b/src/rosdiscover/cli.py
index 81b6cc9c..8c018f8f 100644
--- a/src/rosdiscover/cli.py
+++ b/src/rosdiscover/cli.py
@@ -26,7 +26,7 @@ def _launch(config: Config) -> SystemSummary:
                                ) as interpreter:
         for fn_launch in config.launches:
             logger.info(f"simulating launch [{fn_launch}]")
-            interpreter.launch(fn_launch)
+            interpreter.launch(fn_launch, config)
         return interpreter.summarise()
 
 
diff --git a/src/rosdiscover/interpreter/context.py b/src/rosdiscover/interpreter/context.py
index 6eca22ed..692b046f 100644
--- a/src/rosdiscover/interpreter/context.py
+++ b/src/rosdiscover/interpreter/context.py
@@ -4,6 +4,7 @@
 from loguru import logger
 import attr
 import dockerblade
+from roswire import App
 import roswire.name as rosname
 import typing
 
@@ -24,6 +25,7 @@ class NodeContext:
     args: str
     remappings: Mapping[str, str]
     launch_filename: str
+    app: "App" = attr.ib(repr=False)
     _params: ParameterServer = attr.ib(repr=False)
     _files: dockerblade.files.FileSystem = attr.ib(repr=False)
     _nodelet: bool = attr.ib(default=False, repr=False)
diff --git a/src/rosdiscover/interpreter/interpreter.py b/src/rosdiscover/interpreter/interpreter.py
index 9bfa8050..5dc552e0 100644
--- a/src/rosdiscover/interpreter/interpreter.py
+++ b/src/rosdiscover/interpreter/interpreter.py
@@ -10,6 +10,7 @@
 from .model import Model
 from .summary import SystemSummary
 from .parameter import ParameterServer
+from ..config import Config
 
 
 class Interpreter:
@@ -43,7 +44,7 @@ def summarise(self) -> SystemSummary:
         node_to_summary = {s.fullname: s for s in node_summaries}
         return SystemSummary(node_to_summary)
 
-    def launch(self, filename: str) -> None:
+    def launch(self, filename: str, configuration: Config) -> None:
         """Simulates the effects of `roslaunch` using a given launch file."""
         # NOTE this method also supports command-line arguments
         reader = LaunchFileReader(shell=self._app.shell,
@@ -68,7 +69,8 @@ def launch(self, filename: str) -> None:
                            namespace=node.namespace,  # FIXME
                            launch_filename=node.filename,
                            remappings=remappings,
-                           args=args)
+                           args=args,
+                           config=configuration)
             # FIXME this is waaay too permissive
             except Exception:
                 logger.exception(f"failed to launch node: {node.name}")
@@ -90,6 +92,7 @@ def _load_nodelet(self,
                       namespace: str,
                       launch_filename: str,
                       remappings: Dict[str, str],
+                      config: Config,
                       manager: Optional[str] = None
                       ) -> None:
         """Loads a nodelet using the provided instructions.
@@ -132,7 +135,8 @@ def _load_nodelet(self,
                           namespace=namespace,
                           launch_filename=launch_filename,
                           remappings=remappings,
-                          args='')
+                          args='',
+                          config=config)
 
     def _load(self,
               pkg: str,
@@ -141,7 +145,8 @@ def _load(self,
               namespace: str,
               launch_filename: str,
               remappings: Dict[str, str],
-              args: str
+              args: str,
+              config: Config
               ) -> None:
         """Loads a node using the provided instructions.
 
@@ -182,7 +187,8 @@ def _load(self,
                                           name=name,
                                           namespace=namespace,
                                           launch_filename=launch_filename,
-                                          remappings=remappings)
+                                          remappings=remappings,
+                                          config=config)
             else:
                 load, pkg_and_nodetype, mgr = args.split(' ')
                 pkg, _, nodetype = pkg_and_nodetype.partition('/')
@@ -192,7 +198,8 @@ def _load(self,
                                           namespace=namespace,
                                           launch_filename=launch_filename,
                                           remappings=remappings,
-                                          manager=mgr)
+                                          manager=mgr,
+                                          config=config)
 
         if remappings:
             logger.info(f"using remappings: {remappings}")
@@ -213,7 +220,8 @@ def _load(self,
                           launch_filename=launch_filename,
                           remappings=remappings,
                           files=self._app.files,
-                          params=self.params)
+                          params=self.params,
+                          app=config.app)
         self.nodes[ctx.fullname] = ctx
 
         model.eval(ctx)