diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,8 @@
+# 0.1.1 [2020-12-27]
+
+- Mark all modules as `Safe`.
+  See https://gitlab.haskell.org/ghc/ghc/-/issues/19127
+
 # 0.1 [2020-12-15]
 
 - Split out and combine this package functionality from `lens` and `optics`
diff --git a/indexed-traversable.cabal b/indexed-traversable.cabal
--- a/indexed-traversable.cabal
+++ b/indexed-traversable.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.12
 name:               indexed-traversable
-version:            0.1
+version:            0.1.1
 build-type:         Simple
 license:            BSD2
 license-file:       LICENSE
@@ -56,7 +56,10 @@
   default-language: Haskell2010
   ghc-options:      -Wall
   hs-source-dirs:   src
-  other-modules:    WithIndex
+  other-modules:
+    GhcExts
+    WithIndex
+
   exposed-modules:
     Data.Foldable.WithIndex
     Data.Functor.WithIndex
diff --git a/src/Data/Foldable/WithIndex.hs b/src/Data/Foldable/WithIndex.hs
--- a/src/Data/Foldable/WithIndex.hs
+++ b/src/Data/Foldable/WithIndex.hs
@@ -1,3 +1,9 @@
+{-# LANGUAGE CPP         #-}
+#if __GLASGOW_HASKELL__ >= 704
+{-# LANGUAGE Safe        #-}
+#elif __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 -- | Indexed Foldables.
 module Data.Foldable.WithIndex (
     -- * Indexed Foldables
@@ -24,8 +30,8 @@
 import Control.Monad       (liftM, void)
 import Data.Foldable       (Foldable, any)
 import Data.Monoid         (All (..), Any (..))
-import GHC.Exts            (build)
 
+import GhcExts (build)
 import WithIndex
 
 -- | Return whether or not any element in a container satisfies a predicate, with access to the index @i@.
diff --git a/src/Data/Functor/WithIndex.hs b/src/Data/Functor/WithIndex.hs
--- a/src/Data/Functor/WithIndex.hs
+++ b/src/Data/Functor/WithIndex.hs
@@ -1,3 +1,9 @@
+{-# LANGUAGE CPP         #-}
+#if __GLASGOW_HASKELL__ >= 704
+{-# LANGUAGE Safe        #-}
+#elif __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Data.Functor.WithIndex (
     -- * Indexed Functors
     FunctorWithIndex(..),
diff --git a/src/Data/Traversable/WithIndex.hs b/src/Data/Traversable/WithIndex.hs
--- a/src/Data/Traversable/WithIndex.hs
+++ b/src/Data/Traversable/WithIndex.hs
@@ -1,3 +1,9 @@
+{-# LANGUAGE CPP         #-}
+#if __GLASGOW_HASKELL__ >= 704
+{-# LANGUAGE Safe        #-}
+#elif __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 -- | Indexed Traversables
 module Data.Traversable.WithIndex (
     -- * Indexed Traversables
diff --git a/src/GhcExts.hs b/src/GhcExts.hs
new file mode 100644
--- /dev/null
+++ b/src/GhcExts.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE CPP         #-}
+#if __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
+module GhcExts (
+    build,
+) where
+
+import GHC.Exts (build)