diff --git a/lib/brush.hpp b/lib/brush.hpp
index fcf423250..dbb4ffc7c 100644
--- a/lib/brush.hpp
+++ b/lib/brush.hpp
@@ -66,8 +66,12 @@ class Brush {
   bool stroke_to (Surface * surface, float x, float y, float pressure, float xtilt, float ytilt, double dtime, float viewzoom, float viewrotation, float barrel_rotation, bool linear)
   {
       MyPaintSurface *c_surface = surface->get_surface_interface();
-      bool retval = mypaint_brush_stroke_to(c_brush, c_surface, x, y, pressure, xtilt, ytilt, dtime, viewzoom, viewrotation, barrel_rotation, linear);
-      return retval;
+      bool stroke_finished_or_empty;
+
+      Py_BEGIN_ALLOW_THREADS
+          stroke_finished_or_empty = mypaint_brush_stroke_to(c_brush, c_surface, x, y, pressure, xtilt, ytilt, dtime, viewzoom, viewrotation, barrel_rotation, linear);
+      Py_END_ALLOW_THREADS
+      return stroke_finished_or_empty;
   }
 
   double get_total_stroke_painting_time()
diff --git a/lib/pythontiledsurface.cpp b/lib/pythontiledsurface.cpp
index 5a009e476..517dcf31c 100644
--- a/lib/pythontiledsurface.cpp
+++ b/lib/pythontiledsurface.cpp
@@ -36,8 +36,9 @@ tile_request_start(MyPaintTiledSurface *tiled_surface, MyPaintTileRequest *reque
     const int ty = request->ty;
     PyArrayObject* rgba = NULL;
 
-#pragma omp critical
 {
+    PyGILState_STATE gstate = PyGILState_Ensure();
+
     rgba = (PyArrayObject*)PyObject_CallMethod(self->py_obj, "_get_tile_numpy", "(iii)", tx, ty, readonly);
     if (rgba == NULL) {
         request->buffer = NULL;
@@ -59,7 +60,9 @@ tile_request_start(MyPaintTiledSurface *tiled_surface, MyPaintTileRequest *reque
         Py_DECREF((PyObject *)rgba);
         request->buffer = (uint16_t*)PyArray_DATA(rgba);
     }
-} // #end pragma opt critical
+
+    PyGILState_Release(gstate);
+}
 
 
 }
diff --git a/lib/tiledsurface.hpp b/lib/tiledsurface.hpp
index 96b98bfa3..315f0d9b7 100644
--- a/lib/tiledsurface.hpp
+++ b/lib/tiledsurface.hpp
@@ -69,7 +69,9 @@ class TiledSurface : public Surface {
       MyPaintRectangle* rects = this->bbox_rectangles;
       MyPaintRectangles bboxes = {BBOXES, rects};
 
-      mypaint_surface_end_atomic((MyPaintSurface *)c_surface, &bboxes);
+      Py_BEGIN_ALLOW_THREADS
+          mypaint_surface_end_atomic((MyPaintSurface *)c_surface, &bboxes);
+      Py_END_ALLOW_THREADS
 
       // The capacity of the bounding box array will most often exceed the number
       // of rectangles that are actually used. The call to mypaint_surface_end_atomic