diff --git a/deps/+PNG/PNG.cmake b/deps/+PNG/PNG.cmake
index a186c69dee..4169f42301 100644
--- a/deps/+PNG/PNG.cmake
+++ b/deps/+PNG/PNG.cmake
@@ -5,10 +5,17 @@ else ()
     set(_disable_neon_extension "")
 endif ()
 
+set(_patch_cmd PATCH_COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_LIST_DIR}/genout.cmake.in scripts/genout.cmake.in)
+
+if (APPLE)
+    set(_patch_cmd ${_patch_cmd} && ${PATCH_CMD} ${CMAKE_CURRENT_LIST_DIR}/PNG.patch)
+endif ()
+
 add_cmake_project(PNG 
     URL https://github.com/glennrp/libpng/archive/refs/tags/v1.6.40.zip
     URL_HASH SHA256=ab3f88779f0661bbb07c60e778fda782216bff70355d86848fbf6a327084563a
-    PATCH_COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_LIST_DIR}/genout.cmake.in scripts/genout.cmake.in 
+    #PATCH_COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_LIST_DIR}/genout.cmake.in scripts/genout.cmake.in 
+    PATCH_COMMAND "${_patch_cmd}"
     # SOURCE_DIR /home/quarky/Workspace/prusa3d/PrusaSlicer/prusaslicer-src-master/deps/build-default/dep_PNG-prefix/src/dep_PNG/
     CMAKE_ARGS
         -DPNG_SHARED=OFF
diff --git a/deps/+PNG/PNG.patch b/deps/+PNG/PNG.patch
new file mode 100644
index 0000000000..3e6a70d519
--- /dev/null
+++ b/deps/+PNG/PNG.patch
@@ -0,0 +1,26 @@
+Common subdirectories: ../libpng-1.6.35-orig/arm and ./arm
+Common subdirectories: ../libpng-1.6.35-orig/contrib and ./contrib
+Common subdirectories: ../libpng-1.6.35-orig/intel and ./intel
+Common subdirectories: ../libpng-1.6.35-orig/mips and ./mips
+Only in ./: PNG.patch
+diff -u ../libpng-1.6.35-orig/pngrutil.c ./pngrutil.c
+--- ../libpng-1.6.35-orig/pngrutil.c	2018-07-15 20:58:00.000000000 +0200
++++ ./pngrutil.c	2021-03-24 15:59:38.687108444 +0100
+@@ -422,13 +422,6 @@
+             png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+       }
+ 
+-#if ZLIB_VERNUM >= 0x1290 && \
+-   defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_IGNORE_ADLER32)
+-      if (((png_ptr->options >> PNG_IGNORE_ADLER32) & 3) == PNG_OPTION_ON)
+-         /* Turn off validation of the ADLER32 checksum in IDAT chunks */
+-         ret = inflateValidate(&png_ptr->zstream, 0);
+-#endif
+-
+       if (ret == Z_OK)
+          png_ptr->zowner = owner;
+ 
+Common subdirectories: ../libpng-1.6.35-orig/powerpc and ./powerpc
+Common subdirectories: ../libpng-1.6.35-orig/projects and ./projects
+Common subdirectories: ../libpng-1.6.35-orig/scripts and ./scripts
+Common subdirectories: ../libpng-1.6.35-orig/tests and ./tests