diff --git a/pkgs/applications/networking/irc/weechat/default.nix b/pkgs/applications/networking/irc/weechat/default.nix
index 78b497364a5e..5e5cf8d9002f 100644
--- a/pkgs/applications/networking/irc/weechat/default.nix
+++ b/pkgs/applications/networking/irc/weechat/default.nix
@@ -24,7 +24,7 @@ stdenv.mkDerivation rec {
   # then.
   patches = [ ./fix-gnutls-32.diff ];
 
-  NIX_CFLAGS_COMPILE = "-I${python}/include/python2.7";
+  NIX_CFLAGS_COMPILE = "-I${python}/include/${python.libPrefix}";
 
   postInstall = ''
     NIX_PYTHONPATH="$out/lib/${python.libPrefix}/site-packages"
diff --git a/pkgs/applications/networking/irc/weechat/devel.nix b/pkgs/applications/networking/irc/weechat/devel.nix
index 7adfbb0f8e0e..b858203b0f8c 100644
--- a/pkgs/applications/networking/irc/weechat/devel.nix
+++ b/pkgs/applications/networking/irc/weechat/devel.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
       cacert cmake ]
     ++ stdenv.lib.optional stdenv.isDarwin pythonPackages.pync;
 
-  NIX_CFLAGS_COMPILE = "-I${python}/include/python2.7";
+  NIX_CFLAGS_COMPILE = "-I${python}/include/${python.libPrefix}";
 
   postInstall = ''
     NIX_PYTHONPATH="$out/lib/${python.libPrefix}/site-packages"