diff --git a/rules-tests/TypeDeclaration/Rector/StmtsAwareInterface/SafeDeclareStrictTypesRector/Fixture/skip_with_include_file.php.inc b/rules-tests/TypeDeclaration/Rector/StmtsAwareInterface/SafeDeclareStrictTypesRector/Fixture/skip_with_include_file.php.inc
new file mode 100644
index 00000000000..5e23db4bdab
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/StmtsAwareInterface/SafeDeclareStrictTypesRector/Fixture/skip_with_include_file.php.inc
@@ -0,0 +1,8 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\StmtsAwareInterface\SafeDeclareStrictTypesRector\Fixture;
+
+// this included file is not safe
+include __DIR__ . '/../Source/NonTypedApp.php';
+
+echo strlen('1');
diff --git a/rules-tests/TypeDeclaration/Rector/StmtsAwareInterface/SafeDeclareStrictTypesRector/Source/NonTypedApp.php b/rules-tests/TypeDeclaration/Rector/StmtsAwareInterface/SafeDeclareStrictTypesRector/Source/NonTypedApp.php
new file mode 100644
index 00000000000..a036b1dbebb
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/StmtsAwareInterface/SafeDeclareStrictTypesRector/Source/NonTypedApp.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\StmtsAwareInterface\SafeDeclareStrictTypesRector\Source;
+
+final class NonTypedApp
+{
+    public function callDynamic(string $func): void
+    {
+        $func('arg');
+    }
+}
+
+$a = new NonTypedApp();
+$a->callDynamic('phpinfo');
diff --git a/rules/TypeDeclaration/NodeAnalyzer/StrictTypeSafetyChecker.php b/rules/TypeDeclaration/NodeAnalyzer/StrictTypeSafetyChecker.php
index 1a7e787db3f..b4bcc5ee66b 100644
--- a/rules/TypeDeclaration/NodeAnalyzer/StrictTypeSafetyChecker.php
+++ b/rules/TypeDeclaration/NodeAnalyzer/StrictTypeSafetyChecker.php
@@ -8,6 +8,7 @@
 use PhpParser\Node\Attribute;
 use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\CallLike;
+use PhpParser\Node\Expr\Include_;
 use PhpParser\Node\Expr\PropertyFetch;
 use PhpParser\Node\Expr\StaticPropertyFetch;
 use PhpParser\Node\FunctionLike;
@@ -68,7 +69,8 @@ public function isFileStrictTypeSafe(FileNode $fileNode): bool
             }
         }
 
-        return true;
+        $includes = $this->betterNodeFinder->findInstanceOf($fileNode->stmts, Include_::class);
+        return $includes === [];
     }
 
     private function isCallLikeSafe(CallLike $callLike): bool