diff --git a/src/Settings/Warnings.hs b/src/Settings/Warnings.hs
index abbc8142910d88bd7ec9b99db8cac09d8c34240d..8c42217e62b076119cb06be7d66eb36e4584f67e 100644
--- a/src/Settings/Warnings.hs
+++ b/src/Settings/Warnings.hs
@@ -32,6 +32,8 @@ warningArgs = builder Ghc ? do
         , package binary       ? pure [ "-Wno-deprecations" ]
         , package bytestring   ? pure [ "-Wno-inline-rule-shadowing" ]
         , package compiler     ? pure [ "-Wcpp-undef" ]
+        -- FIXME: See https://phabricator.haskell.org/D4121#117481.
+        , input "//SysTools.hs" ? pure [ "-Wno-unused-imports" ]
         , package directory    ? pure [ "-Wno-unused-imports" ]
         , package ghc          ? pure [ "-Wcpp-undef" ]
         , package ghcPrim      ? pure [ "-Wno-trustworthy-safe" ]