--- a/toolkit/crashreporter/crashreporter.mozbuild
+++ b/toolkit/crashreporter/crashreporter.mozbuild
@@ -8,16 +8,22 @@ LOCAL_INCLUDES += [
     '/toolkit/crashreporter/breakpad-client',
     '/toolkit/crashreporter/google-breakpad/src',
 ]
 
 # Suppress warnings in third-party code.
 if CONFIG['_MSC_VER']:
     CXXFLAGS += [
         '-wd4005', # macro redefinition
+        '-wd4146', # negative unsigned
+        '-wd4334', # 32-bit shift to 64 bits
+        '-wd4804', # unsafe use of type 'bool'
+    ]
+    CFLAGS += [
+        '-wd4312', # conversion to greater size
     ]
 elif CONFIG['GNU_CXX']:
     CXXFLAGS += [
         '-Wno-unused-local-typedefs',
         '-Wno-shadow',
         '-Wno-deprecated-declarations',
         '-Wno-bool-compare',
         '-Wno-unused-but-set-variable',