diff --git a/src/houdini/lib/H_USD/HUSD/HUSD_OutputProcessor.C b/src/houdini/lib/H_USD/HUSD/HUSD_OutputProcessor.C
index 7edc8487..217e6a11 100644
--- a/src/houdini/lib/H_USD/HUSD/HUSD_OutputProcessor.C
+++ b/src/houdini/lib/H_USD/HUSD/HUSD_OutputProcessor.C
@@ -371,7 +371,13 @@ husd_RegistryHolder::husd_RegistryHolder()
             myRegistry.registerOutputProcessor(basename, processor);
         }
     }
-    UT_Exit::addExitCallback(clearRegistryCallback, this);
+
+    // Register a callback to clean up the registry at exit time.
+    // Note that registry cleanup can involve executing Python code
+    // so we want the callback to run at Python exit time.
+    std::function<void(void)> clear_registry_func = 
+	std::bind(&husd_RegistryHolder::clearRegistryCallback, this); 
+    PYregisterAtExitCallback(clear_registry_func);
 }
 
 void
diff --git a/src/houdini/lib/H_USD/gusd/agentUtils.cpp b/src/houdini/lib/H_USD/gusd/agentUtils.cpp
index d547f0cd..6aab791f 100644
--- a/src/houdini/lib/H_USD/gusd/agentUtils.cpp
+++ b/src/houdini/lib/H_USD/gusd/agentUtils.cpp
@@ -422,7 +422,12 @@ Gusd_CreateCaptureAttributes(
                         }
 
                         for (int c = 0; c < tupleSize; ++c) {
-                            indexPair->setIndex(captureAttr, o, c, indices[c]);
+                            // Unused influences have both an index and weight
+                            // of 0. Convert this back to an invalid index for
+                            // the capture attribute.
+                            indexPair->setIndex(
+                                captureAttr, o, c,
+                                (weights[c] == 0.0) ? -1 : indices[c]);
                             indexPair->setData(captureAttr, o, c, weights[c]);
                         }
                     }