diff --git a/rules-tests/TypeDeclarationDocblocks/Rector/Class_/ClassMethodArrayDocblockParamFromLocalCallsRector/Fixture/skip_union_mixed_array.php.inc b/rules-tests/TypeDeclarationDocblocks/Rector/Class_/ClassMethodArrayDocblockParamFromLocalCallsRector/Fixture/skip_union_mixed_array.php.inc
new file mode 100644
index 00000000000..4218fc66e20
--- /dev/null
+++ b/rules-tests/TypeDeclarationDocblocks/Rector/Class_/ClassMethodArrayDocblockParamFromLocalCallsRector/Fixture/skip_union_mixed_array.php.inc
@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Fixture;
+
+class SkipUnionMixedArray
+{
+    public function run()
+    {
+        $this->exec($_SERVER['argv'] ?? []);
+    }
+
+    private function exec(array $argv)
+    {
+    }
+}
\ No newline at end of file
diff --git a/rules/TypeDeclaration/NodeAnalyzer/CallTypesResolver.php b/rules/TypeDeclaration/NodeAnalyzer/CallTypesResolver.php
index 1dff26fafb2..68ae54b0fcb 100644
--- a/rules/TypeDeclaration/NodeAnalyzer/CallTypesResolver.php
+++ b/rules/TypeDeclaration/NodeAnalyzer/CallTypesResolver.php
@@ -135,6 +135,15 @@ private function unionToSingleType(array $staticTypesByArgumentPosition, bool $r
             if ($staticTypeByArgumentPosition[$position]->isNull()->yes()) {
                 $staticTypeByArgumentPosition[$position] = new MixedType();
             }
+
+            if ($staticTypeByArgumentPosition[$position] instanceof UnionType) {
+                foreach ($staticTypeByArgumentPosition[$position]->getTypes() as $subType) {
+                    if ($subType instanceof MixedType) {
+                        $staticTypeByArgumentPosition[$position] = new MixedType();
+                        continue 2;
+                    }
+                }
+            }
         }
 
         return $staticTypeByArgumentPosition;