diff --git a/depends/packages/native_qt.mk b/depends/packages/native_qt.mk
index c975c1e9aba..913d0fc444e 100644
--- a/depends/packages/native_qt.mk
+++ b/depends/packages/native_qt.mk
@@ -10,6 +10,7 @@ $(package)_patches += qtbase_skip_tools.patch
 $(package)_patches += rcc_hardcode_timestamp.patch
 $(package)_patches += qttools_skip_dependencies.patch
 $(package)_patches += fix-macos26-qyield.patch
+$(package)_patches += fix_missed_headers.patch
 
 $(package)_qttranslations_file_name=$(qt_details_qttranslations_file_name)
 $(package)_qttranslations_sha256_hash=$(qt_details_qttranslations_sha256_hash)
@@ -140,7 +141,8 @@ define $(package)_preprocess_cmds
   patch -p1 -i $($(package)_patch_dir)/qtbase_skip_tools.patch && \
   patch -p1 -i $($(package)_patch_dir)/rcc_hardcode_timestamp.patch && \
   patch -p1 -i $($(package)_patch_dir)/qttools_skip_dependencies.patch && \
-  patch -p1 -i $($(package)_patch_dir)/fix-macos26-qyield.patch
+  patch -p1 -i $($(package)_patch_dir)/fix-macos26-qyield.patch && \
+  patch -p1 -i $($(package)_patch_dir)/fix_missed_headers.patch
 endef
 
 define $(package)_config_cmds
diff --git a/depends/packages/qt.mk b/depends/packages/qt.mk
index a88902df8c7..cd4c3cc7d50 100644
--- a/depends/packages/qt.mk
+++ b/depends/packages/qt.mk
@@ -28,6 +28,7 @@ $(package)_patches += fix-macos26-qyield.patch
 $(package)_patches += fix-qbytearray-include.patch
 $(package)_patches += fix_openbsd_network_kernel.patch
 $(package)_patches += fix_openbsd_plugin_qelfparser.patch
+$(package)_patches += fix_missed_headers.patch
 
 $(package)_qttranslations_file_name=$(qt_details_qttranslations_file_name)
 $(package)_qttranslations_sha256_hash=$(qt_details_qttranslations_sha256_hash)
@@ -293,7 +294,8 @@ define $(package)_preprocess_cmds
   patch -p1 -i $($(package)_patch_dir)/fix-macos26-qyield.patch && \
   patch -p1 -i $($(package)_patch_dir)/fix-qbytearray-include.patch && \
   patch -p1 -i $($(package)_patch_dir)/fix_openbsd_network_kernel.patch && \
-  patch -p1 -i $($(package)_patch_dir)/fix_openbsd_plugin_qelfparser.patch
+  patch -p1 -i $($(package)_patch_dir)/fix_openbsd_plugin_qelfparser.patch && \
+  patch -p1 -i $($(package)_patch_dir)/fix_missed_headers.patch
 endef
 ifeq ($(host),$(build))
   $(package)_preprocess_cmds += && patch -p1 -i $($(package)_patch_dir)/qttools_skip_dependencies.patch
diff --git a/depends/patches/qt/fix_missed_headers.patch b/depends/patches/qt/fix_missed_headers.patch
new file mode 100644
index 00000000000..1fda902cef7
--- /dev/null
+++ b/depends/patches/qt/fix_missed_headers.patch
@@ -0,0 +1,32 @@
+QXcbAtom: add missing <cstdlib> #include
+
+Clang 21 complained about free() being an undefined identifier.
+
+See: https://codereview.qt-project.org/c/qt/qtbase/+/686891
+
+--- a/qtbase/src/plugins/platforms/xcb/qxcbatom.cpp
++++ b/qtbase/src/plugins/platforms/xcb/qxcbatom.cpp
+@@ -7,6 +7,7 @@
+ #include <string.h>
+ 
+ #include <algorithm>
++#include <cstdlib>
+ 
+ static const char *xcb_atomnames = {
+     // window-manager <-> client protocols
+
+
+syncqt.cpp: Include <algorithm> for std::transform
+
+See: https://codereview.qt-project.org/c/qt/qtbase/+/673183
+
+--- a/qtbase/src/tools/syncqt/main.cpp
++++ b/qtbase/src/tools/syncqt/main.cpp
+@@ -15,6 +15,7 @@
+  * pre-defined list of header files.
+  */
+ 
++#include <algorithm>
+ #include <iostream>
+ #include <fstream>
+ #include <string>