diff --git a/pkgs/development/arduino/ino/default.nix b/pkgs/development/arduino/ino/default.nix
index be3799d01968..47c7c68c1ab2 100644
--- a/pkgs/development/arduino/ino/default.nix
+++ b/pkgs/development/arduino/ino/default.nix
@@ -1,5 +1,5 @@
 { stdenv, fetchurl, buildPythonPackage, pythonPackages, picocom
-, avrdude, arduino_core, avrgcclibc }:
+, avrdude, arduino-core, avrgcclibc }:
 
 buildPythonPackage rec {
   name = "ino-0.3.6";
@@ -12,12 +12,12 @@ buildPythonPackage rec {
 
   # TODO: add avrgcclibc, it must be rebuild with C++ support
   propagatedBuildInputs =
-    [ arduino_core avrdude picocom pythonPackages.configobj
+    [ arduino-core avrdude picocom pythonPackages.configobj
       pythonPackages.jinja2 pythonPackages.pyserial pythonPackages.six ];
 
   patchPhase = ''
     echo "Patching Arduino distribution path"
-    sed -i 's@/usr/local/share/arduino@${arduino_core}/share/arduino@g' \
+    sed -i 's@/usr/local/share/arduino@${arduino-core}/share/arduino@g' \
         ino/environment.py
     sed -i -e 's@argparse@@' -e 's@ordereddict@@' \
         requirements.txt
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index c6ae8dcb0bb1..3b4d74aec156 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -499,7 +499,7 @@ let
 
   arcanist = callPackage ../development/tools/misc/arcanist {};
 
-  arduino_core = callPackage ../development/arduino/arduino-core {
+  arduino-core = callPackage ../development/arduino/arduino-core {
     jdk = jdk;
     jre = jdk;
   };
@@ -13399,6 +13399,7 @@ let
 
   # Attributes for backward compatibility.
   adobeReader = adobe-reader;
+  arduino_core = arduino-core;  # added 2015-02-04
   asciidocFull = asciidoc-full;  # added 2014-06-22
   lttngTools = lttng-tools;  # added 2014-07-31
   lttngUst = lttng-ust;  # added 2014-07-31