diff --git a/kclvm/evaluator/src/node.rs b/kclvm/evaluator/src/node.rs
index a80f99504..68dffc920 100644
--- a/kclvm/evaluator/src/node.rs
+++ b/kclvm/evaluator/src/node.rs
@@ -78,48 +78,17 @@ impl<'ctx> TypedResultWalker<'ctx> for Evaluator<'ctx> {
         self.add_target_var(name);
         // The right value of the unification_stmt is a schema_expr.
         let value = self.walk_schema_expr(&unification_stmt.value.node)?;
-        if self.scope_level() == GLOBAL_LEVEL || self.is_in_lambda() {
-            if self.resolve_variable(name) {
-                let mut org_value = self.walk_identifier_with_ctx(
-                    &unification_stmt.target.node,
-                    &ast::ExprContext::Load,
-                    None,
-                )?;
-                let value = org_value.bin_aug_bit_or(&mut self.runtime_ctx.borrow_mut(), &value);
-                // Store the identifier value
-                self.walk_identifier_with_ctx(
-                    &unification_stmt.target.node,
-                    &ast::ExprContext::Store,
-                    Some(value.clone()),
-                )?;
-                return Ok(value.clone());
-            } else {
-                self.walk_identifier_with_ctx(
-                    &unification_stmt.target.node,
-                    &unification_stmt.target.node.ctx,
-                    Some(value.clone()),
-                )?;
-                return Ok(value);
-            }
-        // Local variables including schema/rule/lambda
-        } else if self.is_in_schema() {
-            // Load the identifier value
-            let org_value = self
-                .walk_identifier_with_ctx(
-                    &unification_stmt.target.node,
-                    &ast::ExprContext::Load,
-                    None,
-                )
-                .unwrap_or(self.undefined_value());
-            let value = self.bit_or(org_value, value);
-            // Store the identifier value
-            self.walk_identifier_with_ctx(
-                &unification_stmt.target.node,
-                &ast::ExprContext::Store,
-                Some(value.clone()),
-            )?;
-            return Ok(value);
-        }
+        // Load the identifier value
+        let org_value = self
+            .walk_identifier_with_ctx(&unification_stmt.target.node, &ast::ExprContext::Load, None)
+            .unwrap_or(self.undefined_value());
+        let value = self.bit_or(org_value, value);
+        // Store the identifier value
+        self.walk_identifier_with_ctx(
+            &unification_stmt.target.node,
+            &ast::ExprContext::Store,
+            Some(value.clone()),
+        )?;
         self.pop_target_var();
         Ok(value)
     }
diff --git a/test/grammar/schema/config_op/union/union_3/main.k b/test/grammar/schema/config_op/union/union_3/main.k
new file mode 100644
index 000000000..5fd791c44
--- /dev/null
+++ b/test/grammar/schema/config_op/union/union_3/main.k
@@ -0,0 +1,62 @@
+schema ResourceMapping:
+    [str]: any
+
+schema BaseFrontend:
+    name: str
+
+protocol MixinProtocol:
+    count: int
+    resources: ResourceMapping
+
+mixin Mixin1Mixin for MixinProtocol:
+    resources: ResourceMapping {
+        resource1 += [{
+            a = "a"
+        }]
+    }
+    count += 1
+
+mixin Mixin2Mixin for MixinProtocol:
+    resources: ResourceMapping {
+        resource2 += [{
+            b = "b"
+        }]
+    }
+    count += 1
+
+mixin Mixin3Mixin for MixinProtocol:
+    resources: ResourceMapping {
+        resource3 += [{
+            c = "c"
+        }]
+    }
+    count += 1
+
+schema BaseBackend[a: BaseFrontend]:
+    mixin [
+        Mixin1Mixin,
+        Mixin2Mixin,
+        Mixin3Mixin,
+        Mixin3Mixin,
+    ]
+    resources: ResourceMapping
+    count: int = 0
+
+render = lambda a: BaseFrontend {
+    impl = BaseBackend(a)
+    impl
+}
+frontEnd = BaseFrontend {name = "app"}
+res1 = [render(a) for a in BaseFrontend.instances()]
+res2 = [BaseBackend(a) for a in BaseFrontend.instances()]
+resources: ResourceMapping {}
+resources: ResourceMapping {
+    resource1 += [{
+        a = "a"
+    }]
+}
+resources: ResourceMapping {
+    resource2 += [{
+        b = "b"
+    }]
+}
diff --git a/test/grammar/schema/config_op/union/union_3/stdout.golden b/test/grammar/schema/config_op/union/union_3/stdout.golden
new file mode 100644
index 000000000..9b19f672b
--- /dev/null
+++ b/test/grammar/schema/config_op/union/union_3/stdout.golden
@@ -0,0 +1,27 @@
+frontEnd:
+  name: app
+res1:
+- resources:
+    resource1:
+    - a: a
+    resource2:
+    - b: b
+    resource3:
+    - c: c
+    - c: c
+  count: 4
+res2:
+- resources:
+    resource1:
+    - a: a
+    resource2:
+    - b: b
+    resource3:
+    - c: c
+    - c: c
+  count: 4
+resources:
+  resource1:
+  - a: a
+  resource2:
+  - b: b