diff --git a/pkgs/development/interpreters/ruby/ruby-1.8.7.nix b/pkgs/development/interpreters/ruby/ruby-1.8.7.nix
index 90f08df09214..3c2ea71ecf26 100644
--- a/pkgs/development/interpreters/ruby/ruby-1.8.7.nix
+++ b/pkgs/development/interpreters/ruby/ruby-1.8.7.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -75,6 +75,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {
diff --git a/pkgs/development/interpreters/ruby/ruby-1.9.3.nix b/pkgs/development/interpreters/ruby/ruby-1.9.3.nix
index a6c946289fcd..db807ebbd8b3 100644
--- a/pkgs/development/interpreters/ruby/ruby-1.9.3.nix
+++ b/pkgs/development/interpreters/ruby/ruby-1.9.3.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -93,6 +93,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {
diff --git a/pkgs/development/interpreters/ruby/ruby-2.0.0.nix b/pkgs/development/interpreters/ruby/ruby-2.0.0.nix
index 111350bd915d..31408b738072 100644
--- a/pkgs/development/interpreters/ruby/ruby-2.0.0.nix
+++ b/pkgs/development/interpreters/ruby/ruby-2.0.0.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -77,6 +77,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {
diff --git a/pkgs/development/interpreters/ruby/ruby-2.1.0.nix b/pkgs/development/interpreters/ruby/ruby-2.1.0.nix
index 3657b9b6255f..95ab84eedb8e 100644
--- a/pkgs/development/interpreters/ruby/ruby-2.1.0.nix
+++ b/pkgs/development/interpreters/ruby/ruby-2.1.0.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchgit, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchgit, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -92,8 +92,15 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
+
   meta = {
     license = stdenv.lib.licenses.ruby;
     homepage = "http://www.ruby-lang.org/en/";
diff --git a/pkgs/development/interpreters/ruby/ruby-2.1.1.nix b/pkgs/development/interpreters/ruby/ruby-2.1.1.nix
index fc534cdb9f19..abd09c0f2768 100644
--- a/pkgs/development/interpreters/ruby/ruby-2.1.1.nix
+++ b/pkgs/development/interpreters/ruby/ruby-2.1.1.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchgit, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchgit, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -91,6 +91,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {
diff --git a/pkgs/development/interpreters/ruby/ruby-2.1.2.nix b/pkgs/development/interpreters/ruby/ruby-2.1.2.nix
index 3d5156768e55..8612cd6bd439 100644
--- a/pkgs/development/interpreters/ruby/ruby-2.1.2.nix
+++ b/pkgs/development/interpreters/ruby/ruby-2.1.2.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchgit, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchgit, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -90,6 +90,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {
diff --git a/pkgs/development/interpreters/ruby/ruby-2.1.3.nix b/pkgs/development/interpreters/ruby/ruby-2.1.3.nix
index 694fa4a5e02a..1ba97daac04f 100644
--- a/pkgs/development/interpreters/ruby/ruby-2.1.3.nix
+++ b/pkgs/development/interpreters/ruby/ruby-2.1.3.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchgit, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchgit, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -94,6 +94,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {
diff --git a/pkgs/development/interpreters/ruby/ruby-2.2.0.nix b/pkgs/development/interpreters/ruby/ruby-2.2.0.nix
index 9a22a75e621e..0fb01a5a5350 100644
--- a/pkgs/development/interpreters/ruby/ruby-2.2.0.nix
+++ b/pkgs/development/interpreters/ruby/ruby-2.2.0.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchgit, fetchFromGitHub
+{ stdenv, lib, fetchurl, fetchgit, fetchFromGitHub
 , zlib, zlibSupport ? true
 , openssl, opensslSupport ? true
 , gdbm, gdbmSupport ? true
@@ -85,6 +85,12 @@ stdenv.mkDerivation rec {
 
     envHooks+=(addGemPath)
     EOF
+  '' + lib.optionalString useRailsExpress ''
+    rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
+
+    # Prevent the baseruby from being included in the closure.
+    sed -i '/^  CONFIG\["BASERUBY"\]/d' $rbConfig
+    sed -i "s|'--with-baseruby=${baseruby}/bin/ruby'||" $rbConfig
   '';
 
   meta = {