diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1c314679b..0162cd46d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -373,6 +373,7 @@ list(
   src/dwarfs/category_parser.cpp
   src/dwarfs/checksum.cpp
   src/dwarfs/chmod_transformer.cpp
+  src/dwarfs/chmod_entry_transformer.cpp
   src/dwarfs/console_writer.cpp
   src/dwarfs/entry.cpp
   src/dwarfs/error.cpp
diff --git a/include/dwarfs/chmod_entry_transformer.h b/include/dwarfs/chmod_entry_transformer.h
new file mode 100644
index 000000000..ff7c6cb79
--- /dev/null
+++ b/include/dwarfs/chmod_entry_transformer.h
@@ -0,0 +1,35 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/**
+ * \author     Marcus Holland-Moritz (github@mhxnet.de)
+ * \copyright  Copyright (c) Marcus Holland-Moritz
+ *
+ * This file is part of dwarfs.
+ *
+ * dwarfs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * dwarfs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with dwarfs.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <memory>
+#include <string_view>
+
+#include "dwarfs/entry_transformer.h"
+
+namespace dwarfs {
+
+std::unique_ptr<entry_transformer>
+create_chmod_entry_transformer(std::string_view spec, uint16_t umask);
+
+} // namespace dwarfs
diff --git a/include/dwarfs/chmod_transformer.h b/include/dwarfs/chmod_transformer.h
index d02dd16b9..cc18f69fd 100644
--- a/include/dwarfs/chmod_transformer.h
+++ b/include/dwarfs/chmod_transformer.h
@@ -23,13 +23,29 @@
 
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <string_view>
 
-#include "dwarfs/entry_transformer.h"
-
 namespace dwarfs {
 
-std::unique_ptr<entry_transformer>
-create_chmod_transformer(std::string_view spec, uint16_t umask);
+class chmod_transformer {
+ public:
+  chmod_transformer(std::string_view spec, uint16_t umask);
+
+  std::optional<uint16_t> transform(uint16_t mode, bool isdir) const {
+    return impl_->transform(mode, isdir);
+  }
+
+  class impl {
+   public:
+    virtual ~impl() = default;
+
+    virtual std::optional<uint16_t>
+    transform(uint16_t mode, bool isdir) const = 0;
+  };
+
+ private:
+  std::unique_ptr<impl> impl_;
+};
 
 } // namespace dwarfs
diff --git a/src/dwarfs/chmod_entry_transformer.cpp b/src/dwarfs/chmod_entry_transformer.cpp
new file mode 100644
index 000000000..da161324d
--- /dev/null
+++ b/src/dwarfs/chmod_entry_transformer.cpp
@@ -0,0 +1,53 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/**
+ * \author     Marcus Holland-Moritz (github@mhxnet.de)
+ * \copyright  Copyright (c) Marcus Holland-Moritz
+ *
+ * This file is part of dwarfs.
+ *
+ * dwarfs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * dwarfs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with dwarfs.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "dwarfs/chmod_entry_transformer.h"
+#include "dwarfs/chmod_transformer.h"
+#include "dwarfs/entry_interface.h"
+
+namespace dwarfs {
+
+namespace {
+
+class chmod_entry_transformer : public entry_transformer {
+ public:
+  chmod_entry_transformer(std::string_view spec, uint16_t umask)
+      : transformer_{spec, umask} {}
+
+  void transform(entry_interface& ei) override {
+    if (auto perm =
+            transformer_.transform(ei.get_permissions(), ei.is_directory())) {
+      ei.set_permissions(perm.value());
+    }
+  }
+
+ private:
+  chmod_transformer transformer_;
+};
+
+} // namespace
+
+std::unique_ptr<entry_transformer>
+create_chmod_entry_transformer(std::string_view spec, uint16_t umask) {
+  return std::make_unique<chmod_entry_transformer>(spec, umask);
+}
+
+} // namespace dwarfs
diff --git a/src/dwarfs/chmod_transformer.cpp b/src/dwarfs/chmod_transformer.cpp
index ea908064c..f7584ed20 100644
--- a/src/dwarfs/chmod_transformer.cpp
+++ b/src/dwarfs/chmod_transformer.cpp
@@ -30,7 +30,6 @@
 #include <fmt/format.h>
 
 #include "dwarfs/chmod_transformer.h"
-#include "dwarfs/entry_interface.h"
 
 namespace dwarfs {
 
@@ -151,11 +150,11 @@ class dynamic_permission_modifier : public permission_modifier {
   uint16_t const umask_;
 };
 
-class chmod_transformer : public entry_transformer {
+class chmod_transformer_ : public chmod_transformer::impl {
  public:
-  chmod_transformer(std::string_view spec, uint16_t umask);
+  chmod_transformer_(std::string_view spec, uint16_t umask);
 
-  void transform(entry_interface& ei) override;
+  std::optional<uint16_t> transform(uint16_t mode, bool isdir) const override;
 
  private:
   std::unique_ptr<permission_modifier const> modifier_;
@@ -163,7 +162,7 @@ class chmod_transformer : public entry_transformer {
   bool flag_F_{false};
 };
 
-chmod_transformer::chmod_transformer(std::string_view spec, uint16_t umask) {
+chmod_transformer_::chmod_transformer_(std::string_view spec, uint16_t umask) {
   enum class state { PARSE_WHERE, PARSE_PERMS, PARSE_OCTAL };
   state st{state::PARSE_WHERE};
   oper op{oper::NONE};
@@ -344,21 +343,19 @@ chmod_transformer::chmod_transformer(std::string_view spec, uint16_t umask) {
   }
 }
 
-void chmod_transformer::transform(entry_interface& ei) {
+std::optional<uint16_t>
+chmod_transformer_::transform(uint16_t mode, bool isdir) const {
   // skip entries for which this isn't intended
-  if ((flag_D_ and !ei.is_directory()) or (flag_F_ and ei.is_directory())) {
-    return;
+  if ((flag_D_ and !isdir) or (flag_F_ and isdir)) {
+    return std::nullopt;
   }
 
-  ei.set_permissions(
-      modifier_->modify(ei.get_permissions(), ei.is_directory()));
+  return modifier_->modify(mode, isdir);
 }
 
 } // namespace
 
-std::unique_ptr<entry_transformer>
-create_chmod_transformer(std::string_view spec, uint16_t umask) {
-  return std::make_unique<chmod_transformer>(spec, umask);
-}
+chmod_transformer::chmod_transformer(std::string_view spec, uint16_t umask)
+    : impl_{std::make_unique<chmod_transformer_>(spec, umask)} {}
 
 } // namespace dwarfs
diff --git a/src/mkdwarfs_main.cpp b/src/mkdwarfs_main.cpp
index db8cf3abc..eb4ddced2 100644
--- a/src/mkdwarfs_main.cpp
+++ b/src/mkdwarfs_main.cpp
@@ -55,7 +55,7 @@
 #include "dwarfs/builtin_script.h"
 #include "dwarfs/categorizer.h"
 #include "dwarfs/category_parser.h"
-#include "dwarfs/chmod_transformer.h"
+#include "dwarfs/chmod_entry_transformer.h"
 #include "dwarfs/console_writer.h"
 #include "dwarfs/entry.h"
 #include "dwarfs/error.h"
@@ -894,7 +894,7 @@ int mkdwarfs_main(int argc, sys_char** argv) {
       ::umask(mask);             /* Flawfinder: ignore */
 
       for (auto expr : chmod_exprs) {
-        bs->add_transformer(create_chmod_transformer(expr, mask));
+        bs->add_transformer(create_chmod_entry_transformer(expr, mask));
       }
     }