diff --git a/acinclude.m4 b/acinclude.m4
index a66a3746..3fd96236 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -64,4 +64,9 @@ AC_DEFUN([COMPILER_FLAGS], [
 			CFLAGS+=" -Wcast-align"
 		fi
 	fi
+
+	if (test "$CC" = "clang"); then
+		CFLAGS+=" -Wno-unknown-warning-option"
+		CFLAGS+=" -Wno-unknown-pragmas"
+	fi
 ])