diff --git a/testsuite/MDAnalysisTests/analysis/test_encore.py b/testsuite/MDAnalysisTests/analysis/test_encore.py
index 9204352f48..3e9cda17f5 100644
--- a/testsuite/MDAnalysisTests/analysis/test_encore.py
+++ b/testsuite/MDAnalysisTests/analysis/test_encore.py
@@ -157,7 +157,7 @@ def test_parallel_calculation(self):
         arguments = [tuple([i]) for i in np.arange(0, 100)]
 
         parallel_calculation = encore.utils.ParallelCalculation(
-            function=function, n_jobs=4, args=arguments
+            function=function, n_jobs=2, args=arguments
         )
         results = parallel_calculation.run()
 
@@ -173,14 +173,14 @@ def test_rmsd_matrix_with_superimposition(self, ens1):
             encore.confdistmatrix.conformational_distance_matrix(
                 ens1,
                 encore.confdistmatrix.set_rmsd_matrix_elements,
-                select="name CA",
+                select="name CA and resnum 1:3",
                 pairwise_align=True,
                 weights="mass",
                 n_jobs=1,
             )
         )
 
-        reference = rms.RMSD(ens1, select="name CA")
+        reference = rms.RMSD(ens1, select="name CA and resnum 1:3")
         reference.run()
         err_msg = (
             "Calculated RMSD values differ from "
@@ -200,7 +200,7 @@ def test_rmsd_matrix_with_superimposition_custom_weights(self, ens1):
             encore.confdistmatrix.conformational_distance_matrix(
                 ens1,
                 encore.confdistmatrix.set_rmsd_matrix_elements,
-                select="name CA",
+                select="name CA and resnum 1:3",
                 pairwise_align=True,
                 weights="mass",
                 n_jobs=1,
@@ -211,11 +211,11 @@ def test_rmsd_matrix_with_superimposition_custom_weights(self, ens1):
             encore.confdistmatrix.conformational_distance_matrix(
                 ens1,
                 encore.confdistmatrix.set_rmsd_matrix_elements,
-                select="name CA",
+                select="name CA and resnum 1:3",
                 pairwise_align=True,
                 weights=(
-                    ens1.select_atoms("name CA").masses,
-                    ens1.select_atoms("name CA").masses,
+                    ens1.select_atoms("name CA and resnum 1:3").masses,
+                    ens1.select_atoms("name CA and resnum 1:3").masses,
                 ),
                 n_jobs=1,
             )
@@ -230,7 +230,7 @@ def test_rmsd_matrix_with_superimposition_custom_weights(self, ens1):
             )
 
     def test_rmsd_matrix_without_superimposition(self, ens1):
-        selection_string = "name CA"
+        selection_string = "name CA and resnum 1:3"
         selection = ens1.select_atoms(selection_string)
         reference_rmsd = []
         coordinates = ens1.trajectory.timeseries(selection, order="fac")
diff --git a/testsuite/MDAnalysisTests/parallelism/test_multiprocessing.py b/testsuite/MDAnalysisTests/parallelism/test_multiprocessing.py
index b4648d16bc..572bd1fffd 100644
--- a/testsuite/MDAnalysisTests/parallelism/test_multiprocessing.py
+++ b/testsuite/MDAnalysisTests/parallelism/test_multiprocessing.py
@@ -89,8 +89,8 @@
         ),
         (NCDF,),
         (np.arange(150).reshape(5, 10, 3).astype(np.float64),),
-        (GRO, [GRO, GRO, GRO, GRO, GRO]),
-        (PDB, [PDB, PDB, PDB, PDB, PDB]),
+        (GRO, [GRO, GRO]),
+        (PDB, [PDB, PDB]),
         (GRO, [XTC, XTC]),
         (TRC_PDB_VAC, TRC_TRAJ1_VAC),
         (TRC_PDB_VAC, [TRC_TRAJ1_VAC, TRC_TRAJ2_VAC]),
@@ -130,10 +130,10 @@ def cog(u, ag, frame_id):
 def test_multiprocess_COG(u):
     ag = u.atoms[2:5]
 
-    ref = np.array([cog(u, ag, i) for i in range(3)])
+    ref = np.array([cog(u, ag, i) for i in range(2)])
 
     p = multiprocessing.Pool(2)
-    res = np.array([p.apply(cog, args=(u, ag, i)) for i in range(3)])
+    res = np.array([p.apply(cog, args=(u, ag, i)) for i in range(2)])
     p.close()
     assert_equal(ref, res)
 
@@ -145,10 +145,10 @@ def getnames(u, ix):
 
 def test_universe_unpickle_in_new_process():
     u = mda.Universe(GRO, XTC)
-    ref = [getnames(u, i) for i in range(3)]
+    ref = [getnames(u, i) for i in range(2)]
 
     p = multiprocessing.Pool(2)
-    res = [p.apply(getnames, args=(u, i)) for i in range(3)]
+    res = [p.apply(getnames, args=(u, i)) for i in range(2)]
     p.close()
 
     assert_equal(ref, res)
@@ -206,9 +206,9 @@ def test_creating_multiple_universe_without_offset(temp_xtc, ncopies=3):
         ("memory", np.arange(60).reshape(2, 10, 3).astype(np.float64), dict()),
         ("TRC", TRC_TRAJ1_VAC, dict()),
         ("CHAIN", [TRC_TRAJ1_VAC, TRC_TRAJ2_VAC], dict()),
-        ("CHAIN", [GRO, GRO, GRO], dict()),
-        ("CHAIN", [PDB, PDB, PDB], dict()),
-        ("CHAIN", [XTC, XTC, XTC], dict()),
+        ("CHAIN", [GRO, GRO], dict()),
+        ("CHAIN", [PDB, PDB], dict()),
+        ("CHAIN", [XTC, XTC], dict()),
     ]
 )
 def ref_reader(request):