diff --git a/Data/IP/Addr.hs b/Data/IP/Addr.hs
--- a/Data/IP/Addr.hs
+++ b/Data/IP/Addr.hs
@@ -405,7 +405,7 @@
   where
     test errmsg adr = when (adr < 0 || 255 < adr) (fail errmsg)
     check as = do
-        let errmsg = "IPv4 adddress"
+        let errmsg = "IPv4 address"
         when (length as /= 4) (fail errmsg)
         mapM_ (test errmsg) as
 
diff --git a/iproute.cabal b/iproute.cabal
--- a/iproute.cabal
+++ b/iproute.cabal
@@ -1,5 +1,5 @@
 Name:                   iproute
-Version:                1.7.6
+Version:                1.7.7
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3
@@ -21,11 +21,11 @@
   Exposed-Modules:      Data.IP
                         Data.IP.Internal
                         Data.IP.RouteTable
+                        Data.IP.RouteTable.Internal
   Other-Modules:        Data.IP.Addr
                         Data.IP.Mask
                         Data.IP.Op
                         Data.IP.Range
-                        Data.IP.RouteTable.Internal
   Build-Depends:        base >= 4.6 && < 5
                       , appar
                       , byteorder
@@ -46,7 +46,7 @@
 Test-Suite spec
   Type:                 exitcode-stdio-1.0
   Default-Language:     Haskell2010
-  Hs-Source-Dirs:       ., test
+  Hs-Source-Dirs:       test
   Ghc-Options:          -Wall
   Main-Is:              Spec.hs
   Other-Modules:        RouteTableSpec
@@ -59,6 +59,7 @@
                       , containers
                       , network
                       , safe
+                      , iproute
   if impl(ghc < 8.0)
      Build-Depends:     semigroups >= 0.17