diff --git a/3rdparty/libpng/CMakeLists.txt b/3rdparty/libpng/CMakeLists.txt
index 70f73f13e..d47dd53fc 100644
--- a/3rdparty/libpng/CMakeLists.txt
+++ b/3rdparty/libpng/CMakeLists.txt
@@ -30,6 +30,7 @@ if(MSVC)
 endif(MSVC)
 
 add_library(${PNG_LIBRARY} STATIC ${lib_srcs} ${lib_hdrs})
+target_link_libraries(${PNG_LIBRARY} ${ZLIB_LIBRARY})
 
 if(UNIX)
   if(CMAKE_COMPILER_IS_GNUCXX OR CV_ICC)
diff --git a/android/android.toolchain.cmake b/android/android.toolchain.cmake
index b4d498fc3..53bb0e54a 100644
--- a/android/android.toolchain.cmake
+++ b/android/android.toolchain.cmake
@@ -796,6 +796,7 @@ set( CMAKE_ASM_COMPILER_ID GNU )
 set( CMAKE_ASM_COMPILER_WORKS TRUE )
 set( CMAKE_ASM_COMPILER_FORCED TRUE )
 set( CMAKE_COMPILER_IS_GNUASM 1)
+set( CMAKE_ASM_SOURCE_FILE_EXTENSIONS s S asm )
 
 # NDK flags
 if( ARMEABI OR ARMEABI_V7A )