diff --git a/src/build/cli.cr b/src/build/cli.cr
index b957f60..b625c41 100644
--- a/src/build/cli.cr
+++ b/src/build/cli.cr
@@ -28,6 +28,10 @@ module DocMachine::Build
           config.port = port.to_i
         end
 
+        opts.on("-m", "--multiple", "Allow multiple instances per dir" ) do |port|
+          config.multiple_instances = true
+        end
+
         opts.on("-t", "--tty", "Enable TTY mode (needed for shell)") do
           config.enable_tty = true
         end
diff --git a/src/build/config.cr b/src/build/config.cr
index 8129259..5831af6 100644
--- a/src/build/config.cr
+++ b/src/build/config.cr
@@ -5,6 +5,7 @@ module DocMachine::Build
     property action : String = "watch"
     property enable_tty : Bool = false
     property port : Int32 = 5100
+    property multiple_instances : Bool = false
 
     def initialize(@parent : DocMachine::Config)
     end
diff --git a/src/build/run.cr b/src/build/run.cr
index f95591c..67549df 100644
--- a/src/build/run.cr
+++ b/src/build/run.cr
@@ -11,7 +11,8 @@ module DocMachine::Build
     Log = DocMachine::Build::Log.for("run")
 
     def initialize(@config : DocMachine::Build::Config)
-      @basehash = Digest::SHA256.hexdigest(@config.data_dir)[0..6]
+      data = "#{@config.data_dir}:#{@config.port}"
+      @basehash = Digest::SHA256.hexdigest(data)[0..6]
       @docker_name = "docmachine-#{@basehash}"
       @docker_image = "glenux/docmachine:latest"
       @docker_opts = [] of String
@@ -27,8 +28,8 @@ module DocMachine::Build
       Log.info { "docker_image = #{@docker_image}" }
       Log.info { "action       = #{@config.action}" }
 
-      self._avoid_duplicates()
       self._pull_image()
+      self._avoid_duplicates() unless @config.multiple_instances
     end
 
     private def _find_port(port_base)
@@ -48,13 +49,15 @@ module DocMachine::Build
     end
 
     private def _avoid_duplicates
+      Log.info { "Multiple Instances: stopping duplicate containers (for #{@docker_name})" }
       docker_cid = %x{docker ps -f "name=#{@docker_name}" -q}.strip
 
-      Log.info { "docker_name: #{@docker_name}" }
-      Log.info { "docker_cid: #{docker_cid}" }
+      Log.info { "Multiple Instances: docker_name: #{@docker_name}" }
+      Log.info { "Multiple Instances: docker_cid: #{docker_cid || "-"}" }
 
       if !docker_cid.empty?
         Process.run("docker", ["kill", @docker_name])
+        Process.run("docker", ["rm", @docker_name])
       end
     end