diff --git a/mfem/_par/bilinearform.i b/mfem/_par/bilinearform.i
index 43216089..697e42ee 100644
--- a/mfem/_par/bilinearform.i
+++ b/mfem/_par/bilinearform.i
@@ -75,6 +75,7 @@ namespace mfem {
    %} 
 %pythonprepend MixedBilinearForm::AddDomainIntegrator %{
     if not hasattr(self, "_integrators"): self._integrators = []
+    bfi = args[0]
     self._integrators.append(bfi)
     bfi.thisown=0
    %}
@@ -93,7 +94,8 @@ namespace mfem {
     if not hasattr(self, "_integrators"): self._integrators = []
     bfi = args[0]	     
     self._integrators.append(bfi)
-    bfi.thisown=0
+    self.UseExternalIntegrators()
+    #bfi.thisown=0
    %} 
 %pythonappend MixedBilinearForm::SpMat %{
     if not hasattr(self, "_spmat"): self._spmat = []
@@ -102,11 +104,13 @@ namespace mfem {
    %}
 %pythonprepend DiscreteLinearOperator::AddDomainInterpolator %{
     if not hasattr(self, "_integrators"): self._integrators = []
+    di = args[0]
     self._integrators.append(di)
     di.thisown=0
    %} 
 %pythonprepend DiscreteLinearOperator::AddTraceFaceInterpolator %{
     if not hasattr(self, "_integrators"): self._integrators = []
+    di = args[0]
     self._integrators.append(di)
     di.thisown=0
    %}
diff --git a/mfem/_par/nonlinearform.i b/mfem/_par/nonlinearform.i
index 83d70fc9..546b6428 100644
--- a/mfem/_par/nonlinearform.i
+++ b/mfem/_par/nonlinearform.i
@@ -23,6 +23,7 @@ import_array();
 namespace mfem { 
 %pythonprepend NonlinearForm::AddDomainIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
+    nlfi = args[0]	     
 #    self._integrators.append(nlfi)
     nlfi.thisown=0 
 %}
@@ -33,13 +34,14 @@ namespace mfem {
 %}
 %pythonprepend NonlinearForm::AddBdrFaceIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
+    nlfi = args[0]     
 #    self._integrators.append(nlfi)
-    nlfi = args[0]
     nlfi.thisown=0 
 %}
 %pythonprepend BlockNonlinearForm::AddDomainIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
-#    self._integrators.append(nlfi)
+    nlfi = args[0]
+#    self._integrators.append(nlfi)      
     nlfi.thisown=0 
 %}
 %pythonprepend BlockNonlinearForm::AddInteriorFaceIntegrator %{
@@ -49,8 +51,8 @@ namespace mfem {
 %}
 %pythonprepend BlockNonlinearForm::AddBdrFaceIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
+    nlfi = args[0]	     
 #    self._integrators.append(nlfi)
-    nlfi = args[0]
     nlfi.thisown=0 
 %}
 }
diff --git a/mfem/_ser/bilinearform.i b/mfem/_ser/bilinearform.i
index 2907c613..37c9f670 100644
--- a/mfem/_ser/bilinearform.i
+++ b/mfem/_ser/bilinearform.i
@@ -75,6 +75,7 @@ namespace mfem {
    %} 
 %pythonprepend MixedBilinearForm::AddDomainIntegrator %{
     if not hasattr(self, "_integrators"): self._integrators = []
+    bfi = args[0]
     self._integrators.append(bfi)
     bfi.thisown=0
    %}
@@ -103,11 +104,13 @@ namespace mfem {
    %}
 %pythonprepend DiscreteLinearOperator::AddDomainInterpolator %{
     if not hasattr(self, "_integrators"): self._integrators = []
+    di = args[0]
     self._integrators.append(di)
     di.thisown=0
    %} 
 %pythonprepend DiscreteLinearOperator::AddTraceFaceInterpolator %{
     if not hasattr(self, "_integrators"): self._integrators = []
+    di = args[0]
     self._integrators.append(di)
     di.thisown=0
     %}
diff --git a/mfem/_ser/nonlinearform.i b/mfem/_ser/nonlinearform.i
index 4f35dd86..eeae8c5b 100644
--- a/mfem/_ser/nonlinearform.i
+++ b/mfem/_ser/nonlinearform.i
@@ -26,6 +26,7 @@ import_array();
 namespace mfem { 
 %pythonprepend NonlinearForm::AddDomainIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
+    nlfi = args[0]	     
 #    self._integrators.append(nlfi)
     nlfi.thisown=0 
 %}
@@ -36,13 +37,14 @@ namespace mfem {
 %}
 %pythonprepend NonlinearForm::AddBdrFaceIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
-#    self._integrators.append(nlfi)
     nlfi = args[0]
+#    self._integrators.append(nlfi)	     
     nlfi.thisown=0 
 %}
 %pythonprepend BlockNonlinearForm::AddDomainIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
-#    self._integrators.append(nlfi)
+    nlfi = args[0]
+#    self._integrators.append(nlfi)	     
     nlfi.thisown=0 
 %}
 %pythonprepend BlockNonlinearForm::AddInteriorFaceIntegrator %{
@@ -52,8 +54,8 @@ namespace mfem {
 %}
 %pythonprepend BlockNonlinearForm::AddBdrFaceIntegrator %{
 #    if not hasattr(self, "_integrators"): self._integrators = []
+    nlfi = args[0]	     
 #    self._integrators.append(nlfi)
-    nlfi = args[0]
     nlfi.thisown=0 
 %}
 }