diff --git a/changelog/63933.fixed.md b/changelog/63933.fixed.md
new file mode 100644
index 00000000000..794c170bd04
--- /dev/null
+++ b/changelog/63933.fixed.md
@@ -0,0 +1,4 @@
+Issue 63933: Fixes an issue with `saltclass.expanded_dict_from_minion`
+function where it was passing a reference to minion `dict` which was
+overridden by nested classes during class expansion. Copy the node
+definition with `copy.deepcopy` instead of passing a reference.
diff --git a/salt/utils/saltclass.py b/salt/utils/saltclass.py
index 1f6df19d128..c18d01af3d1 100644
--- a/salt/utils/saltclass.py
+++ b/salt/utils/saltclass.py
@@ -1,3 +1,4 @@
+import copy
 import glob
 import logging
 import os
@@ -362,7 +363,9 @@ def expanded_dict_from_minion(minion_id, salt_data):
         node_dict[minion_id] = {}
 
     # Merge newly found pillars into existing ones
-    dict_merge(salt_data["__pillar__"], node_dict[minion_id].get("pillars", {}))
+    dict_merge(
+        salt_data["__pillar__"], copy.deepcopy(node_dict[minion_id]).get("pillars", {})
+    )
 
     # Get 2 ordered lists:
     # expanded_classes: A list of all the dicts