diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -7,3 +7,13 @@
   * Drop support for GHC 8.6
   * Add support for GHC 8.8 and 8.10
   * Tighten dependency bounds
+
+1.1.0.1 - 2021 Mar 9
+
+  * Change dependency from `rando` to `mwc-random`
+    for generating random coupon codes
+
+  * Relax dependency bounds
+
+  * Remove `lens` dependency (although `wreq`
+    incurs it transitively anyway)
diff --git a/leanpub-wreq.cabal b/leanpub-wreq.cabal
--- a/leanpub-wreq.cabal
+++ b/leanpub-wreq.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.0
 
 name: leanpub-wreq
-version: 1.1
+version: 1.1.0.1
 
 synopsis: Use the Leanpub API via Wreq
 category: Web
@@ -35,15 +35,14 @@
         Leanpub.Wreq
 
     build-depends:
-        aeson ^>=1.5
+        aeson ^>= 1.4 || ^>=1.5
       , base ^>= 4.13 || ^>= 4.14
-      , bytestring ^>= 0.11
+      , bytestring ^>= 0.10 || ^>= 0.11
       , exceptions ^>= 0.10
-      , lens ^>= 5.0
       , leanpub-concepts ^>= 1.0 || ^>= 1.1
-      , rando ^>= 0.0
-      , text ^>= 1.2.3
-      , time ^>= 1.11
+      , mwc-random ^>= 0.15
+      , text ^>= 1.2.4
+      , time ^>= 1.9 || ^>= 1.11
       , transformers ^>=0.5
       , unordered-containers ^>= 0.2.13
       , wreq ^>= 0.5.3
diff --git a/library/Leanpub/Wreq.hs b/library/Leanpub/Wreq.hs
--- a/library/Leanpub/Wreq.hs
+++ b/library/Leanpub/Wreq.hs
@@ -30,6 +30,9 @@
 import Control.Monad hiding (fail, foldM)
 import Control.Monad.IO.Class
 import Control.Monad.Fail
+import Data.Function ((&))
+import Data.Functor.Const
+import Data.Functor.Identity
 import qualified Data.List
 import Data.Maybe
 import Data.Monoid
@@ -44,11 +47,8 @@
 -- leanpub-concepts
 import Leanpub.Concepts
 
--- lens
-import Control.Lens ((&), (.~), (^.))
-
--- rando
-import System.Random.Pick (pickOne)
+-- mwc-random
+import System.Random.MWC (GenIO, createSystemRandom, uniformRM)
 
 -- text
 import           Data.Text (Text)
@@ -68,6 +68,22 @@
 import           Network.Wreq.Session (Session, newAPISession)
 import qualified Network.Wreq.Session
 
+------------------------------------------------------------
+
+-- from the 'lens' library
+
+type Getting r s a = (a -> Const r a) -> s -> Const r s
+
+(^.) :: s -> Getting a s a -> a
+s ^. l = getConst (l Const s)
+
+type ASetter s t a b = (a -> Identity b) -> s -> Identity t
+
+(.~) :: ASetter s t a b -> b -> s -> t
+l .~ b = fmap runIdentity $ l (\_ -> Identity b)
+
+------------------------------------------------------------
+
 text :: String -> Text
 text = Data.Text.pack
 
@@ -290,10 +306,11 @@
   do
     requireKey
     start <- liftIO getToday
+    g <- liftIO createSystemRandom
 
     (sequence_ . replicate (fromIntegral n))
       do
-        code <- liftIO randomCouponCode
+        code <- liftIO (randomCouponCode g)
         wreqPostAeson_
             [slug, text "coupons"]
             (freeBookParams start code uses noteMaybe)
@@ -327,11 +344,17 @@
 formatDay :: Day -> String
 formatDay = Data.Time.formatTime Data.Time.defaultTimeLocale "%Y-%m-%d"
 
-randomCouponCode :: IO CouponCode
-randomCouponCode =
+randomCouponCode :: GenIO -> IO CouponCode
+randomCouponCode g =
   do
     s <- sequence (Data.List.replicate 20 randomChar)
     return (CouponCode (text s))
   where
-    randomChar = pickOne charset
+    randomChar = pickOne g charset
     charset = ['a'..'z'] ++ ['0'..'9']
+
+pickOne :: GenIO -> [a] -> IO a
+pickOne g xs =
+  do
+    i <- uniformRM (0, length xs - 1) g
+    return (xs !! i)