diff --git a/Host.hs b/Host.hs
--- a/Host.hs
+++ b/Host.hs
@@ -32,8 +32,8 @@
     [ (`Host` defaultTalkatPort) <$> decodeIPv6 s
     , do
         i <- lastMay $ elemIndices ':' s
-        let (h, ':':portStr) = splitAt i s
-            h' = fromMaybe h $ decodeIPv6 h
+        (h, ':':portStr) <- Just $ splitAt i s
+        let h' = fromMaybe h $ decodeIPv6 h
         Host h' <$> readMay portStr
     , pure $ Host s defaultTalkatPort
     ]
diff --git a/Identity.hs b/Identity.hs
--- a/Identity.hs
+++ b/Identity.hs
@@ -22,6 +22,7 @@
 import           Data.ASN1.Types          (ASN1Object (..))
 import           Data.ASN1.Types.String   (ASN1StringEncoding (UTF8))
 import           Data.Hourglass
+import           Data.Maybe               (fromJust)
 import           Data.PEM
 import           Data.X509                as X
 
@@ -108,7 +109,7 @@
             connectChain <- generateSelfSigned secKey cn
             listenChain <- generateSelfSigned secKey ""
             saveIdentity ddir (PrivKeyEd25519 secKey) connectChain listenChain
-            let Just cert = takeTailCert connectChain
+            let cert = fromJust $ takeTailCert connectChain
                 fp = spkiFingerprint cert
             putStrLn $ "Your fingerprint: talkat:" <> showFingerprint fp
             writeName ddir (User fp (parseHost "localhost")) $ Named "self"
diff --git a/Petname.hs b/Petname.hs
--- a/Petname.hs
+++ b/Petname.hs
@@ -84,7 +84,7 @@
             MaybeT $ lookupName ddir name
         , do
             i <- MaybeT . pure . lastMay $ elemIndices '@' target
-            let (n, '@':h) = splitAt i target
+            (n, '@':h) <- MaybeT . pure . Just $ splitAt i target
             name <- MaybeT . pure $ parsePetname n
             host <- MaybeT . pure $ parseHost h
             MaybeT $ ((\u -> u { userHost = Just host }) <$>) <$>
diff --git a/TLSTalk.hs b/TLSTalk.hs
--- a/TLSTalk.hs
+++ b/TLSTalk.hs
@@ -23,6 +23,7 @@
 import           Control.Exception
 import           Control.Monad            (void, (<=<))
 import           Data.Default.Class       (def)
+import           Data.Maybe               (fromJust)
 import           Data.X509.Validation     (FailedReason (..), defaultChecks,
                                            defaultHooks, validate)
 import           Network.Simple.TCP       (connectSock, connectSockSOCKS5)
@@ -91,7 +92,7 @@
         hostPref = case listen_host conf of
             [] -> TCP.HostAny
             h  -> TCP.Host h
-        Just fp = spkiFingerprint <$> takeTailCert (fst cred)
+        fp = spkiFingerprint . fromJust . takeTailCert $ fst cred
     putStrLn $ "Listening on "
         <> (case hostPref of
             TCP.Host h -> "host " <> h
diff --git a/Version.hs b/Version.hs
--- a/Version.hs
+++ b/Version.hs
@@ -16,4 +16,4 @@
 programName = "htalkat"
 
 version :: String
-version = "0.1.2.5"
+version = "0.1.2.6"
diff --git a/htalkat.cabal b/htalkat.cabal
--- a/htalkat.cabal
+++ b/htalkat.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.18
 name:               htalkat
-version:            0.1.2.5
+version:            0.1.2.6
 license:            GPL-3
 license-file:       COPYING
 maintainer:         mbays@sdf.org
@@ -62,8 +62,8 @@
         asn1-types >=0.3.4 && <0.4,
         bytestring >=0.10.8.0 && <0.13,
         containers >=0.5.5.1 && <0.8,
-        crypton >=0.26 && <0.35,
-        data-default-class >=0.1.2.0 && <0.2,
+        crypton >=0.26 && <1.1,
+        data-default-class >=0.1.2.0 && <0.3,
         data-hash >=0.2.0.1 && <0.3,
         directory >=1.2.1.0 && <1.4,
         exceptions >=0.10.4 && <0.11,
@@ -81,7 +81,7 @@
         temporary >= 1.2 && <1.4,
         text >=1.1.0.0 && <2.2,
         time <1.15,
-        tls >=1.5.4 && <2.1,
+        tls >=1.5.4 && <2.2,
         transformers >=0.3.0.0 && <0.7,
         crypton-x509 >=1.7.5 && <1.8,
         crypton-x509-validation >=1.6.11 && <1.7
@@ -94,5 +94,5 @@
     if flag(curses)
         cpp-options: -DCURSES
         other-modules: CursesClient
-        build-depends: hscurses <1.5
+        build-depends: hscurses <1.6
         pkgconfig-depends: ncursesw