diff --git a/lib/r10k/puppetfile.rb b/lib/r10k/puppetfile.rb
index 648e88541..070d93913 100644
--- a/lib/r10k/puppetfile.rb
+++ b/lib/r10k/puppetfile.rb
@@ -10,7 +10,7 @@ class Puppetfile
 
   include R10K::Settings::Mixin
 
-  def_setting_attr :pool_size, 4
+  def_setting_attr :pool_size, 1
 
   include R10K::Logging
 
diff --git a/lib/r10k/settings.rb b/lib/r10k/settings.rb
index e29602696..20333dc62 100644
--- a/lib/r10k/settings.rb
+++ b/lib/r10k/settings.rb
@@ -159,8 +159,8 @@ def self.global_settings
         }),
 
         Definition.new(:pool_size, {
-          :desc => "The amount of threads used to concurrently install modules. The default value is 4: install four modules at a time.",
-          :default => 4,
+          :desc => "The amount of threads used to concurrently install modules. The default value is 1: install one module at a time.",
+          :default => 1,
           :validate => lambda do |value|
             if !value.is_a?(Integer)
               raise ArgumentError, "The pool_size setting should be an integer, not a #{value.class}"