diff --git a/src/lasp/pybind11/lasp_pyindatahandler.cpp b/src/lasp/pybind11/lasp_pyindatahandler.cpp
index cf4406b..1a366b7 100644
--- a/src/lasp/pybind11/lasp_pyindatahandler.cpp
+++ b/src/lasp/pybind11/lasp_pyindatahandler.cpp
@@ -96,9 +96,9 @@ py::array_t<d> dmat_to_ndarray(const DaqData &d) {
 }
 
 /**
- * @brief Wraps the ThreadedInDataHandler such that it calls a Python callback with a
- * buffer of sample data. Converts DaqData objects to Numpy arrays and calls
- * Python given as argument to the constructor
+ * @brief Wraps the ThreadedInDataHandler such that it calls a Python callback
+ * with a buffer of sample data. Converts DaqData objects to Numpy arrays and
+ * calls Python given as argument to the constructor
  */
 class PyIndataHandler : public ThreadedInDataHandler<PyIndataHandler> {
   /**
@@ -122,10 +122,14 @@ public:
     DEBUGTRACE_ENTER;
     /// Start should be called externally, as at constructor time no virtual
     /// functions should be called.
+    py::gil_scoped_release release;
     startThread();
   }
   ~PyIndataHandler() {
     DEBUGTRACE_ENTER;
+    /// Callback cannot be called, which results in a deadlock on the GIL
+    /// without this release.
+    py::gil_scoped_release release;
     stopThread();
   }
   /**
@@ -163,8 +167,8 @@ public:
 
     using DataType = DataTypeDescriptor::DataType;
 
-    py::gil_scoped_acquire acquire;
     try {
+      py::gil_scoped_acquire acquire;
       py::object bool_val;
       switch (d.dtype) {
       case (DataType::dtype_int8): {
@@ -195,6 +199,9 @@ public:
       cerr << e.what() << endl;
       cerr << "ERROR: Python callback does not return boolean value." << endl;
       abort();
+    } catch (std::exception &e) {
+      cerr << "Caught unknown exception:" << e.what()  << endl;
+      abort();
     }
   }
 };