diff --git a/src/aiida_quantumespresso/calculations/pw.py b/src/aiida_quantumespresso/calculations/pw.py
index 6a2b420f1..71720b9f3 100644
--- a/src/aiida_quantumespresso/calculations/pw.py
+++ b/src/aiida_quantumespresso/calculations/pw.py
@@ -179,8 +179,15 @@ def validate_inputs(cls, value, port_namespace):
         the ``parent_folder`` input at a later step in the outline. To avoid raising any warnings, such a work chain
         must exclude the ``parent_folder`` port when exposing the inputs of the ``PwCalculation``.
         """
+        from aiida.engine.processes.calcjobs.calcjob import validate_calc_job
+
         result = super().validate_inputs(value, port_namespace)
 
+        if result is not None:
+            return result
+
+        result = validate_calc_job(value, port_namespace)
+
         if result is not None:
             return result
 
diff --git a/tests/workflows/protocols/pw/test_bands/test_default.yml b/tests/workflows/protocols/pw/test_bands/test_default.yml
index 7883f8588..f3ab01bde 100644
--- a/tests/workflows/protocols/pw/test_bands/test_default.yml
+++ b/tests/workflows/protocols/pw/test_bands/test_default.yml
@@ -6,6 +6,7 @@ bands:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CONTROL:
@@ -45,6 +46,7 @@ relax:
           max_wallclock_seconds: 43200
           resources:
             num_machines: 1
+            num_mpiprocs_per_machine: 1
           withmpi: true
       parameters:
         CELL:
@@ -82,6 +84,7 @@ scf:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CONTROL:
diff --git a/tests/workflows/protocols/pw/test_relax/test_default.yml b/tests/workflows/protocols/pw/test_relax/test_default.yml
index 8182ec2b2..10ad26638 100644
--- a/tests/workflows/protocols/pw/test_relax/test_default.yml
+++ b/tests/workflows/protocols/pw/test_relax/test_default.yml
@@ -8,6 +8,7 @@ base:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CELL:
@@ -42,6 +43,7 @@ base_final_scf:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CONTROL:
diff --git a/tests/workflows/protocols/test_pdos/test_default.yml b/tests/workflows/protocols/test_pdos/test_default.yml
index a81e81376..ac1c27ad6 100644
--- a/tests/workflows/protocols/test_pdos/test_default.yml
+++ b/tests/workflows/protocols/test_pdos/test_default.yml
@@ -20,6 +20,7 @@ nscf:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CONTROL:
@@ -61,6 +62,7 @@ scf:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CONTROL:
diff --git a/tests/workflows/protocols/xspectra/test_core/test_default.yml b/tests/workflows/protocols/xspectra/test_core/test_default.yml
index 52f1dd42f..982fac60f 100644
--- a/tests/workflows/protocols/xspectra/test_core/test_default.yml
+++ b/tests/workflows/protocols/xspectra/test_core/test_default.yml
@@ -26,6 +26,7 @@ scf:
         max_wallclock_seconds: 43200
         resources:
           num_machines: 1
+          num_mpiprocs_per_machine: 1
         withmpi: true
     parameters:
       CONTROL:
diff --git a/tests/workflows/protocols/xspectra/test_crystal/test_default.yml b/tests/workflows/protocols/xspectra/test_crystal/test_default.yml
index 0b1b868db..ee0c5bc9b 100644
--- a/tests/workflows/protocols/xspectra/test_crystal/test_default.yml
+++ b/tests/workflows/protocols/xspectra/test_crystal/test_default.yml
@@ -14,6 +14,7 @@ core:
           max_wallclock_seconds: 43200
           resources:
             num_machines: 1
+            num_mpiprocs_per_machine: 1
           withmpi: true
       parameters:
         CONTROL:
@@ -85,6 +86,7 @@ relax:
           max_wallclock_seconds: 43200
           resources:
             num_machines: 1
+            num_mpiprocs_per_machine: 1
           withmpi: true
       parameters:
         CELL: