1 files changed, 3 insertions, 0 deletions
diff --git a/pdfium.gyp b/pdfium.gyp
index 426306d2d0..65caf6f4b7 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -15,6 +15,9 @@
       '_FPDFSDK_LIB',
       '_NO_GDIPLUS_',  # workaround text rendering issues on Windows
       'OPJ_STATIC',
+      'PNG_PREFIX',
+      'PNGPREFIX_H',
+      'PNG_USE_READ_MACROS',
     ],
     'include_dirs': [
       'third_party/freetype/include',