diff --git a/third_party/CMakeLists.txt b/third_party/CMakeLists.txt
index 1c9241c49..9fe4176cf 100644
--- a/third_party/CMakeLists.txt
+++ b/third_party/CMakeLists.txt
@@ -1,3 +1,6 @@
+# Suppress all warnings from third-party projects.
+set_property(DIRECTORY APPEND PROPERTY COMPILE_OPTIONS -w)
+
 if (IS_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/gmock-1.7.0)
   add_subdirectory(gmock-1.7.0)
 endif()