diff --git a/changelog b/changelog
new file mode 100644
--- /dev/null
+++ b/changelog
@@ -0,0 +1,2 @@
+1.2.1
+* Explicitly mark modules as Safe or Trustworthy
diff --git a/src/Data/Universe/Some.hs b/src/Data/Universe/Some.hs
--- a/src/Data/Universe/Some.hs
+++ b/src/Data/Universe/Some.hs
@@ -1,5 +1,12 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE RankNTypes #-}
+-- Data.Type.Equality is Trustworthy since base-4.9
+#if __GLASGOW_HASKELL__ >=704 && MIN_VERSION_base(4,9,0)
+{-# LANGUAGE Safe #-}
+#elif __GLASGOW_HASKELL__ >=702
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Data.Universe.Some (
   UniverseSome (..),
   FiniteSome (..),
diff --git a/src/Data/Universe/Some/TH.hs b/src/Data/Universe/Some/TH.hs
--- a/src/Data/Universe/Some/TH.hs
+++ b/src/Data/Universe/Some/TH.hs
@@ -4,6 +4,11 @@
 #else
 {-# LANGUAGE TemplateHaskell #-}
 #endif
+#if __GLASGOW_HASKELL__ >=704 && MIN_VERSION_template_haskell(2,12,0)
+{-# LANGUAGE Safe #-}
+#elif __GLASGOW_HASKELL__ >=702
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Data.Universe.Some.TH (
   DeriveUniverseSome (..),
   universeSomeQ,
@@ -17,6 +22,9 @@
 import Language.Haskell.TH
 import Language.Haskell.TH.Datatype
 
+-- $setup
+-- >>> :m + Data.Some Data.Universe.Class Data.Universe.Some
+
 -- | Derive the @'UniverseSome' n@ instance.
 --
 -- >>> :set -XGADTs -XTemplateHaskell -XStandaloneDeriving
@@ -27,14 +35,21 @@
 -- >>> deriving instance Show b => Show (Tag b a)
 -- >>> instance Show b => GShow (Tag b) where gshowsPrec = showsPrec
 --
--- >>> ; deriveUniverseSome ''Tag
+-- (@data Unused@ is to workaround bug in older GHCi)
+-- >>> data Unused; $(deriveUniverseSome ''Tag)
+--
 -- >>> universe :: [Some (Tag (Maybe Bool))]
 -- [Some IntTag,Some (BoolTag Nothing),Some (BoolTag (Just False)),Some (BoolTag (Just True))]
 --
 -- 'deriveUniverseSome' variant taking a 'Name' guesses simple class constraints.
 -- If you need more specific, you can specify them:
+-- (Note: on older GHCs this will warn, as the instance definition doesn't have all methods defined).
 --
--- >>> ; deriveUniverseSome [d| instance Universe b => UniverseSome (Tag b) |]
+-- >>> data Tag b a where IntTag :: Tag b Int; BoolTag :: b -> Tag b Bool
+-- >>> deriving instance Show b => Show (Tag b a)
+-- >>> instance Show b => GShow (Tag b) where gshowsPrec = showsPrec
+-- >>> data Unused; $(deriveUniverseSome [d| instance Universe b => UniverseSome (Tag b) |])
+-- ...
 -- >>> universe :: [Some (Tag (Maybe Bool))]
 -- [Some IntTag,Some (BoolTag Nothing),Some (BoolTag (Just False)),Some (BoolTag (Just True))]
 --
diff --git a/universe-some.cabal b/universe-some.cabal
--- a/universe-some.cabal
+++ b/universe-some.cabal
@@ -1,6 +1,6 @@
-name:          universe-some
-version:       1.2
-synopsis:      Universe instances for Some from some
+name:               universe-some
+version:            1.2.1
+synopsis:           Universe instances for Some from some
 description:
   A class for finite and recursively enumerable types and some helper functions for enumerating them
   defined in @universe-base@ package:
@@ -19,15 +19,16 @@
   .
   classes.
 
-homepage:      https://github.com/dmwit/universe
-license:       BSD3
-license-file:  LICENSE
-author:        Daniel Wagner, Oleg Grenrus
-maintainer:    me@dmwit.com
-copyright:     Daniel Wagner 2014, Oleg Grenrus 2019
-category:      Data
-build-type:    Simple
-cabal-version: >=1.10
+homepage:           https://github.com/dmwit/universe
+license:            BSD3
+license-file:       LICENSE
+author:             Daniel Wagner, Oleg Grenrus
+maintainer:         me@dmwit.com
+copyright:          Daniel Wagner 2014, Oleg Grenrus 2019
+category:           Data
+build-type:         Simple
+cabal-version:      >=1.10
+extra-source-files: changelog
 tested-with:
   GHC ==7.0.4
    || ==7.4.2
@@ -38,7 +39,8 @@
    || ==8.2.2
    || ==8.4.4
    || ==8.6.5
-   || ==8.8.1
+   || ==8.8.4
+   || ==8.10.3
 
 source-repository head
   type:     git
@@ -47,7 +49,7 @@
 source-repository this
   type:     git
   location: https://github.com/dmwit/universe
-  tag:      instances-dependent-sum-1.1
+  tag:      universe-1.2.1
 
 library
   default-language: Haskell2010
@@ -57,12 +59,12 @@
     Data.Universe.Some.TH
 
   build-depends:
-      base              >=4.3      && <4.14
-    , some              >=1        && <1.1
-    , template-haskell  >=2.5      && <2.16
-    , th-abstraction    >=0.2.11.0 && <0.4
+      base              >=4.3      && <4.16
+    , some              >=1.0.2    && <1.1
+    , template-haskell  >=2.5      && <2.18
+    , th-abstraction    >=0.4.2.0  && <0.5
     , transformers      >=0.3.0.0  && <0.6
-    , universe-base     >=1.1      && <1.1.2
+    , universe-base     >=1.1.2    && <1.1.3
 
   if !impl(ghc >=7.8)
     build-depends: type-equality >=1 && <1.1
@@ -72,6 +74,11 @@
 
   if !impl(ghc >=7.10.3)
     build-depends: transformers-compat >=0.6.1 && <0.7
+
+  if impl(ghc >=8.10)
+    -- these flags may abort compilation with GHC-8.10
+    -- https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3295
+    ghc-options: -Winferred-safe-imports -Wmissing-safe-haskell-mode
 
 test-suite th-test
   type:             exitcode-stdio-1.0