diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4389ec349..246778646 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,7 +20,7 @@ if( CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
     set( CMAKE_C_FLAGS_RELEASE          "-O4 -DNDEBUG" )
     set( CMAKE_C_FLAGS_RELWITHDEBINFO   "-O2 -g" )
 
-    set( CMAKE_CXX_FLAGS                "${CMAKE_CXX_FLAGS} -Weverything" )
+    set( CMAKE_CXX_FLAGS                "${CMAKE_CXX_FLAGS} -Weverything -Wno-c++98-compat -Wno-padded" )
     set( CMAKE_CXX_FLAGS_DEBUG          "-g" )
     set( CMAKE_CXX_FLAGS_MINSIZEREL     "-Os -DNDEBUG" )
     set( CMAKE_CXX_FLAGS_RELEASE        "-O4 -DNDEBUG" )
diff --git a/thirdparty/CMakeLists.txt b/thirdparty/CMakeLists.txt
index b3401a977..77b4897a5 100644
--- a/thirdparty/CMakeLists.txt
+++ b/thirdparty/CMakeLists.txt
@@ -1,3 +1,8 @@
+if( CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
+    # Suppress warnings entirely; not interesting in third-party code
+    set( CMAKE_CXX_FLAGS                "${CMAKE_CXX_FLAGS} -w" )
+endif()
+
 if( WITH_CRASHREPORTER )
     macro( qt_wrap_ui )
         qt5_wrap_ui( ${ARGN} )