--- a/media/ffvpx/ffvpxcommon.mozbuild
+++ b/media/ffvpx/ffvpxcommon.mozbuild
@@ -71,16 +71,18 @@ elif CONFIG['_MSC_VER']:
         '-wd4133', # 'function' : incompatible types - from 'AVSampleFormat *' to 'int *'
         '-wd4221', # nonstandard extension used
         '-wd4206', # nonstandard extension used
         '-wd4702', # unreachable code
         '-wd4101', # unreferenced local variable
         '-wd4245', # conversion from 'int' to 'uint32_t', signed/unsigned mismatch
         '-wd4703', # potentially uninitialized local pointer
         '-wd4293', # '<<' : shift count negative or too big, undefined behavior
+        '-wd4334', # '<<' : result of 32-bit shift implicitly converted to 64 bits
+        '-wd4996', # The compiler encountered a deprecated declaration.
         # from FFmpeg configure
         '-wd4244', '-wd4127', '-wd4018', '-wd4389', '-wd4146', '-wd4701',
         '-wd4057', '-wd4204', '-wd4706', '-wd4305', '-wd4152', '-wd4324',
         '-we4013', '-wd4100', '-wd4214', '-wd4307', '-wd4273', '-wd4554',
     ]
 
 DEFINES['HAVE_AV_CONFIG_H'] = True