diff --git a/python/tests/reference/Result/compressionY.yaml b/python/tests/reference/Result/compressionY.yaml
index cfe67e692..285002c88 100644
--- a/python/tests/reference/Result/compressionY.yaml
+++ b/python/tests/reference/Result/compressionY.yaml
@@ -5,12 +5,12 @@ solver:
 loadstep:
   - boundary_conditions:
       mechanical:
-        dot_F: [x, 0,       0,
-                0, -1.0e-3, 0,
-                0, 0,       x]
-        P: [0, x, x,
-            x, x, x,
-            x, x, 0]
+        dot_F: [[x, 0,       0],
+                [0, -1.0e-3, 0],
+                [0, 0,       x]]
+        P: [[0, x, x],
+            [x, x, x],
+            [x, x, 0]]
     discretization:
       t: 5
       N: 10
diff --git a/python/tests/reference/Result/tensionY.yaml b/python/tests/reference/Result/tensionY.yaml
index 7b1d8ca43..5db88ce89 100644
--- a/python/tests/reference/Result/tensionY.yaml
+++ b/python/tests/reference/Result/tensionY.yaml
@@ -5,12 +5,12 @@ solver:
 loadstep:
   - boundary_conditions:
       mechanical:
-        dot_F: [x, 0,      0,
-                0, 1.0e-3, 0,
-                0, 0,      x]
-        P: [0, x, x,
-            x, x, x,
-            x, x, 0]
+        dot_F: [[x, 0,      0],
+                [0, 1.0e-3, 0],
+                [0, 0,      x]]
+        P: [[0, x, x],
+            [x, x, x],
+            [x, x, 0]]
     discretization:
       t: 20
       N: 40