diff --git a/dlib/CMakeLists.txt b/dlib/CMakeLists.txt
index c32809326..9daeda02c 100644
--- a/dlib/CMakeLists.txt
+++ b/dlib/CMakeLists.txt
@@ -447,6 +447,8 @@ if (NOT TARGET dlib)
             # If we can't find libpng then statically compile it in.
             include_directories(external/libpng external/zlib)
             set(source_files ${source_files}
+               external/libpng/arm/arm_init.c
+               external/libpng/arm/filter_neon_intrinsics.c
                external/libpng/png.c
                external/libpng/pngerror.c
                external/libpng/pngget.c
@@ -953,4 +955,4 @@ if (COMMAND pybind11_add_module)
    set_target_properties(dlib PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
 endif()
 
-add_library(dlib::dlib ALIAS dlib)
\ No newline at end of file
+add_library(dlib::dlib ALIAS dlib)