diff --git a/iCalendar.cabal b/iCalendar.cabal
--- a/iCalendar.cabal
+++ b/iCalendar.cabal
@@ -1,5 +1,5 @@
 name:                iCalendar
-version:             0.4.0.1
+version:             0.4.0.2
 synopsis:            iCalendar data types, parser, and printer.
 description:         Data definitions, parsing and printing of the iCalendar
                      format (RFC5545).
@@ -19,6 +19,9 @@
 source-repository head
   type:              git
   location:          git://github.com/tingtun/iCalendar.git
+flag network-uri
+   description: Get Network.URI from the network-uri package
+   default: True
 
 library
   exposed-modules:     Text.ICalendar.Types
@@ -31,9 +34,15 @@
                      , Text.ICalendar.Parser.Parameters
                      , Text.ICalendar.Parser.Properties
                      , Paths_iCalendar
+
+  if flag(network-uri)
+    build-depends: network-uri >= 2.6, network >= 2.6 && < 2.7
+  else
+    build-depends: network >= 2.4 && < 2.6
+
   build-depends:       base >=4.5 && <5, time ==1.4.*, data-default >=0.3
-                     , case-insensitive >=0.4, network >=2.4 && <2.6
-                     , bytestring >=0.10 && < 0.11, parsec ==3.1.*
+                     , case-insensitive >=0.4
+                     , bytestring >=0.10 && < 0.11, parsec >=3.1.0
                      , text, containers >= 0.5 && < 0.6, mime ==0.4.*
-                     , mtl ==2.1.*, old-locale, base64-bytestring ==1.0.*
+                     , mtl >=2.1.0, old-locale, base64-bytestring ==1.0.*
   ghc-options:       -Wall