diff --git a/nix/carnix.patch b/nix/carnix.patch
new file mode 100644
index 0000000..ccb83f7
--- /dev/null
+++ b/nix/carnix.patch
@@ -0,0 +1,50 @@
+diff --git a/nix/ofborg-carnix.nix b/nix/ofborg-carnix.nix
+index e974c8f..0094e27 100644
+--- a/nix/ofborg-carnix.nix
++++ b/nix/ofborg-carnix.nix
+@@ -2,12 +2,39 @@
+ { lib, buildPlatform, buildRustCrate, fetchgit }:
+ let kernel = buildPlatform.parsed.kernel.name;
+     abi = buildPlatform.parsed.abi.name;
+-    include = includedFiles: src: builtins.filterSource (path: type:
+-      lib.lists.any (f:
+-        let p = toString (src + ("/" + f)); in
+-        (path == p) || (type == "directory" && lib.strings.hasPrefix path p)
+-      ) includedFiles
+-    ) src;
++    include = includedFiles: src:
++      # The comments assume the `include` field of the Cargo.toml like:
++      # include = [ "foo", "bar" ]
++      # and the package is being built from /mypackage
++      #
++      # includeFiles == [ "foo" "bar" ]
++      let
++        # and includedFileAbsolutePaths == [ "/mypackage/foo" "/mypackage/bar" ]
++        includedFileAbsolutePaths = builtins.map (relativePath: toString (src + ("/" + relativePath))) includedFiles;
++
++        # Return true only when a possible path exactly matches an
++        # absolute path, ie:
++        #
++        #     checkExactMatch "/mypackage/foo" == true
++        #     checkExactMatch "/mypackage/foo/bar" == false
++        #     checkExactMatch "/mypackage/baz" == false
++        checkExactMatch = possiblePath: builtins.elem possiblePath includedFileAbsolutePaths;
++
++        # Return true only when a possible path is a suffix to a
++        # directory described by the include.
++        #
++        #     checkPrefixMatch "/mypackage/buzfoo" == false
++        #     checkPrefixMatch "/mypackage/foo" == false
++        #     checkPrefixMatch "/mypackage/foo/bar" == true
++        #     checkPrefixMatch "/mypackage/baz/foo" == false
++        checkPrefixMatch = possiblePath: lib.lists.any
++          (acceptablePrefix: lib.strings.hasPrefix "${acceptablePrefix}/" possiblePath)
++          includedFileAbsolutePaths;
++
++      in builtins.filterSource (possiblePath: _type:
++          builtins.trace "${possiblePath}" ((checkExactMatch possiblePath) || (checkPrefixMatch possiblePath))
++      )
++    src;
+     updateFeatures = f: up: functions: builtins.deepSeq f (lib.lists.foldl' (features: fun: fun features) (lib.attrsets.recursiveUpdate f up) functions);
+     mapFeatures = features: map (fun: fun { features = features; });
+     mkFeatures = feat: lib.lists.foldl (features: featureName:
diff --git a/nix/update-carnix.sh b/nix/update-carnix.sh
index 281dca2..9ae875a 100755
--- a/nix/update-carnix.sh
+++ b/nix/update-carnix.sh
@@ -2,5 +2,13 @@
 
 cd nix
 
-carnix ./../ofborg/Cargo.lock  --output ./ofborg-carnix.nix
-carnix ./../ircbot/Cargo.lock  --output ./ircbot-carnix.nix
+patched_carnix() {
+    src=$1
+    result=$2
+
+    carnix "$src"  --output "$result"
+    patch -p1 "$result" ./carnix.patch
+}
+
+patched_carnix ./../ofborg/Cargo.lock ./ofborg-carnix.nix
+patched_carnix ./../ircbot/Cargo.lock ./ircbot-carnix.nix