diff --git a/build b/build
index 17fcbea..c6a559e 100755
--- a/build
+++ b/build
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -e
+
 echo "\nBuilding site.js site…\n"
 
 # Start fresh.
diff --git a/deploy b/deploy
index 21770b9..e3b0c06 100755
--- a/deploy
+++ b/deploy
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -e
+
 ./build
 
 echo "Deploying Site.js site using Site.js sync…\n"
diff --git a/install b/install
index 61b5fb6..e044dc3 100755
--- a/install
+++ b/install
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -e
+
 echo "Installing site.js site for development…"
 
 # Install build dependencies.