diff --git a/var/spack/repos/builtin/packages/dia/package.py b/var/spack/repos/builtin/packages/dia/package.py
index 59abc88b15abde3844d94d4335bf2da79e3264f1..03a1ca9df26670e689c6e613a7da0e7cd1dcbc47 100644
--- a/var/spack/repos/builtin/packages/dia/package.py
+++ b/var/spack/repos/builtin/packages/dia/package.py
@@ -33,7 +33,7 @@ class Dia(Package):
     version('0.97.3',    '0e744a0f6a6c4cb6a089e4d955392c3c')
 
     depends_on('intltool', type='build')
-    depends_on('gtkplus@2.6.0:+X')
+    depends_on('gtkplus@2.6.0:')
     depends_on('libxslt')
     depends_on('python')
     depends_on('swig')
diff --git a/var/spack/repos/builtin/packages/emacs/package.py b/var/spack/repos/builtin/packages/emacs/package.py
index e654e9c9c7cbf8eb1c198722e0533790317fb4e4..73f557f96d8f68eb15b9119fe595b1be80b697a1 100644
--- a/var/spack/repos/builtin/packages/emacs/package.py
+++ b/var/spack/repos/builtin/packages/emacs/package.py
@@ -57,7 +57,7 @@ class Emacs(AutotoolsPackage):
     depends_on('giflib', when='+X')
     depends_on('libx11', when='+X')
     depends_on('libxaw', when='+X toolkit=athena')
-    depends_on('gtkplus+X', when='+X toolkit=gtk')
+    depends_on('gtkplus', when='+X toolkit=gtk')
     depends_on('gnutls', when='+tls')
     depends_on('libxpm ^gettext+libunistring', when='+tls')
     depends_on('ncurses+termlib', when='+tls')
diff --git a/var/spack/repos/builtin/packages/gtkplus/package.py b/var/spack/repos/builtin/packages/gtkplus/package.py
index cd9b4205179ec253e122d32a9aa007b9a6ec8e4a..fa001a4a3369c84a83241ed8cfccb7990bb7ea17 100644
--- a/var/spack/repos/builtin/packages/gtkplus/package.py
+++ b/var/spack/repos/builtin/packages/gtkplus/package.py
@@ -35,18 +35,16 @@ class Gtkplus(AutotoolsPackage):
     version('2.24.31', '68c1922732c7efc08df4656a5366dcc3afdc8791513400dac276009b40954658')
     version('2.24.25', '38af1020cb8ff3d10dda2c8807f11e92af9d2fa4045de61c62eedb7fbc7ea5b3')
 
-    variant('X', default=False, description="Enable an X toolkit")
-
     depends_on('pkgconfig', type='build')
 
-    depends_on("atk")
-    depends_on("gdk-pixbuf")
-    depends_on("glib")
-    depends_on("pango")
-    depends_on("pango~X", when='~X')
-    depends_on("pango+X", when='+X')
-    depends_on('gobject-introspection', when='+X')
+    depends_on('atk')
+    depends_on('gdk-pixbuf')
+    depends_on('glib')
     depends_on('shared-mime-info')
+    # Hardcode X11 support (former +X variant),
+    # see #6940 for rationale:
+    depends_on('pango+X')
+    depends_on('gobject-introspection')
 
     patch('no-demos.patch')
 
diff --git a/var/spack/repos/builtin/packages/icedtea/package.py b/var/spack/repos/builtin/packages/icedtea/package.py
index c8c992d0f5b77f24bb621887b08f5d0cd24b03ab..39a3084d00972af477c7443b7a958a20215e9613 100644
--- a/var/spack/repos/builtin/packages/icedtea/package.py
+++ b/var/spack/repos/builtin/packages/icedtea/package.py
@@ -58,7 +58,7 @@ class Icedtea(AutotoolsPackage):
     depends_on('libxcomposite', when='~X', type='build')
     depends_on('libxau', when='~X', type='build')
     depends_on('libxdmcp', when='~X', type='build')
-    depends_on('gtkplus+X', when='~X', type='build')
+    depends_on('gtkplus', when='~X', type='build')
 
     depends_on('libx11', when='+X')
     depends_on('xproto', when='+X')
@@ -71,7 +71,7 @@ class Icedtea(AutotoolsPackage):
     depends_on('libxcomposite', when='+X')
     depends_on('libxau', when='+X')
     depends_on('libxdmcp', when='+X')
-    depends_on('gtkplus+X', when='+X')
+    depends_on('gtkplus', when='+X')
 
     depends_on('freetype@2:')
     depends_on('wget', type='build')
diff --git a/var/spack/repos/builtin/packages/py-pygtk/package.py b/var/spack/repos/builtin/packages/py-pygtk/package.py
index 5a05a3a40260f4e42034dc924e09109e6ff8641a..7edda3dec002f733c71b33d3dc8657beb39d425b 100644
--- a/var/spack/repos/builtin/packages/py-pygtk/package.py
+++ b/var/spack/repos/builtin/packages/py-pygtk/package.py
@@ -38,7 +38,7 @@ class PyPygtk(AutotoolsPackage):
     depends_on('cairo')
     depends_on('glib')
     # for GTK 3.X use pygobject 3.X instead of pygtk
-    depends_on('gtkplus+X@2.24:2.99')
+    depends_on('gtkplus@2.24:2.99')
     depends_on('py-pygobject@2.28:2.99', type=('build', 'run'))
     depends_on('py-py2cairo', type=('build', 'run'))
 
diff --git a/var/spack/repos/builtin/packages/slurm/package.py b/var/spack/repos/builtin/packages/slurm/package.py
index a6f5fc59b5b4f0022bc6678dda21eef8d1a2ad22..06f30730e9bfff9218c7e3f12ce46795b97bfa1d 100644
--- a/var/spack/repos/builtin/packages/slurm/package.py
+++ b/var/spack/repos/builtin/packages/slurm/package.py
@@ -68,7 +68,7 @@ class Slurm(AutotoolsPackage):
     depends_on('readline', when='+readline')
     depends_on('zlib')
 
-    depends_on('gtkplus+X', when='+gtk')
+    depends_on('gtkplus', when='+gtk')
     depends_on('hdf5', when='+hdf5')
     depends_on('hwloc', when='+hwloc')
     depends_on('mariadb', when='+mariadb')
diff --git a/var/spack/repos/builtin/packages/wx/package.py b/var/spack/repos/builtin/packages/wx/package.py
index 4aa1e2f16a7f7b94604f4f497060e76bf78aff73..2799dd2e21ed1805ec3b84927f86af5606ac9713 100644
--- a/var/spack/repos/builtin/packages/wx/package.py
+++ b/var/spack/repos/builtin/packages/wx/package.py
@@ -47,7 +47,7 @@ class Wx(AutotoolsPackage):
     patch('math_include.patch', when='@3.0.1:3.0.2')
 
     depends_on('pkgconfig', type='build')
-    depends_on('gtkplus+X')
+    depends_on('gtkplus')
 
     @when('@:3.0.2')
     def build(self, spec, prefix):