diff --git a/bashrc b/bashrc
index f9b2dbe0..700eebdd 100644
--- a/bashrc
+++ b/bashrc
@@ -198,6 +198,9 @@ if [[ $UNAME = "Darwin" && $USER = "root" ]]; then
 fi
 # The above requires at least Mountain Lion.
 
+# I have only one display
+export DISPLAY=:0
+
 #####   Aliases                     RJ706I  #####
 
 # To get sudo work with aliases.
diff --git a/xsessionrc b/xsessionrc
index 0cb5c2f6..30f74862 100644
--- a/xsessionrc
+++ b/xsessionrc
@@ -25,6 +25,9 @@ echo "USE_VALIDATION_AGENT=true" > ~/.monkeysphere/monkeysphere.conf
 # Enable core files.
 ulimit -c unlimited
 
+# I have only one display
+export DISPLAY=:0
+
 # Start gtk-redshift automatically.
 # Use http://stereopsis.com/flux/map.html to get the coordinates. Replace ", " with ":".
 # Set the coordinates to file ~/.redshiftlocation in format redshiftlocation=60.4666227:26.9459998
diff --git a/zshrc b/zshrc
index e0c5c42c..6f9a8b02 100644
--- a/zshrc
+++ b/zshrc
@@ -130,6 +130,8 @@ if [[ $UNAME = "Darwin" && $USER = "root" ]]; then
 fi
 # The above requires at least Mountain Lion.
 
+# I have only one display
+export DISPLAY=:0
 
 #####   Aliases                     RJ706I  #####