diff --git a/pkgs/applications/networking/irc/weechat/default.nix b/pkgs/applications/networking/irc/weechat/default.nix
index 75e5cc4db43..b29ed46e075 100644
--- a/pkgs/applications/networking/irc/weechat/default.nix
+++ b/pkgs/applications/networking/irc/weechat/default.nix
@@ -20,12 +20,12 @@ let
 in
 
 stdenv.mkDerivation rec {
-  version = "1.5";
+  version = "1.6";
   name = "weechat-${version}";
 
   src = fetchurl {
     url = "http://weechat.org/files/src/weechat-${version}.tar.bz2";
-    sha256 = "0n4cbhh9a7qq6y70ac9b4r0kb7hydwsic99h45ppr2jly322fvij";
+    sha256 = "0d1wcpsxx13clcf1ygcn5hsa1pjkck4xznbjbxphbdxd5whsbv3k";
   };
 
   cmakeFlags = with stdenv.lib; []
@@ -50,7 +50,7 @@ stdenv.mkDerivation rec {
     ++ optional  tclSupport      tcl
     ++ extraBuildInputs;
 
-  NIX_CFLAGS_COMPILE = "-I${python}/include/${python.libPrefix} -DCA_FILE=/etc/ssl/certs/ca-certificates.crt";
+  NIX_CFLAGS_COMPILE = "-I${python}/include/${python.libPrefix}";
 
   postInstall = with stdenv.lib; ''
     NIX_PYTHONPATH="$out/lib/${python.libPrefix}/site-packages"