diff --git a/lib/react_on_rails/ensure_assets_compiled.rb b/lib/react_on_rails/ensure_assets_compiled.rb
index 191c8930b2..6e8c75c8c5 100644
--- a/lib/react_on_rails/ensure_assets_compiled.rb
+++ b/lib/react_on_rails/ensure_assets_compiled.rb
@@ -5,22 +5,36 @@ class EnsureAssetsCompiled
     def self.build
       client_dir = Rails.root.join("client")
       compiled_dirs = COMPILED_DIR_NAMES.map { |dir| Rails.root.join("app", "assets", dir, "generated") }
-      checker = WebpackAssetsStatusChecker.new(client_dir: client_dir, compiled_dirs: compiled_dirs)
+
+      assets_checker = WebpackAssetsStatusChecker.new(client_dir: client_dir, compiled_dirs: compiled_dirs)
+      process_checker = WebpackProcessChecker.new
       compiler = WebpackAssetsCompiler.new
-      new(checker, compiler)
+
+      new(assets_checker, compiler, process_checker)
     end
 
-    attr_reader :webpack_assets_checker, :webpack_assets_compiler, :assets_have_been_compiled
+    attr_reader :webpack_assets_checker, :webpack_assets_compiler, :webpack_process_checker, :assets_have_been_compiled
 
-    def initialize(webpack_assets_checker, webpack_assets_compiler)
+    def initialize(webpack_assets_checker, webpack_assets_compiler, webpack_process_checker)
       @webpack_assets_compiler = webpack_assets_compiler
       @webpack_assets_checker = webpack_assets_checker
+      @webpack_process_checker = webpack_process_checker
       @assets_have_been_compiled = false
     end
 
     def call
-      should_skip_compiling = assets_have_been_compiled || @webpack_assets_checker.up_to_date?
-      webpack_assets_compiler.compile unless should_skip_compiling
+      loop do
+        should_skip_compiling = assets_have_been_compiled || @webpack_assets_checker.up_to_date?
+        break if should_skip_compiling
+
+        if webpack_process_checker.running?
+          sleep 1
+        else
+          webpack_assets_compiler.compile
+          break
+        end
+      end
+
       @assets_have_been_compiled = true
     end
   end
@@ -28,7 +42,7 @@ def call
   class WebpackAssetsCompiler
     def compile
       compile_type(:client)
-      compile_type(:server) if ReactOnRails.configuration.server_bundle_js_file.present?
+      compile_type(:server) if Utils.server_rendering_is_enabled?
     end
 
     private
@@ -37,11 +51,43 @@ def compile_type(type)
       puts "\n\nBuilding Webpack #{type}-rendering assets..."
       build_output = `cd client && npm run build:#{type}`
 
-      if build_output =~ /error/i
-        fail "Error in building assets!\n#{build_output}"
-      end
+      fail "Error in building assets!\n#{build_output}" unless Utils.last_process_completed_successfully?
+
+      puts "Webpack #{type}-rendering assets built. If you are frequently running\n"\
+           "tests, you can run webpack in watch mode to speed up this process.\n\n"
+    end
+  end
+
+  class WebpackProcessChecker
+    def running?
+      client_running = check_running_for_type("client")
+      return client_running unless Utils.server_rendering_is_enabled?
+
+      server_running = check_running_for_type("server")
+
+      fail_if_only_running_for_one_type(client_running, server_running)
+
+      client_running && server_running
+    end
+
+    private
+
+    def fail_if_only_running_for_one_type(client_running, server_running)
+      return unless client_running ^ server_running
+      fail "\n\nError: detected webpack is not running for both types of assets:\n"\
+           "***Webpack Client Process Running?: #{client_running}\n"\
+           "***Webpack Server Process Running?: #{server_running}"
+    end
+
+    def check_running_for_type(type)
+      type = type.to_sym
+
+      response = `pgrep -fl 'bin/webpack\s(\\-w|\\-\\-watch)\s\\-\\-config\s.*#{type}.*\\.js'`
+      is_running = Utils.last_process_completed_successfully?
+
+      puts "#{type} webpack process is running: #{response.ai}" if is_running
 
-      puts "Webpack #{type}-rendering assets built.\n\n"
+      is_running
     end
   end
 end
diff --git a/lib/react_on_rails/utils.rb b/lib/react_on_rails/utils.rb
index 4d342f3f78..6f5a43b835 100644
--- a/lib/react_on_rails/utils.rb
+++ b/lib/react_on_rails/utils.rb
@@ -1,7 +1,17 @@
+require "english"
+
 module ReactOnRails
   module Utils
     def self.object_to_boolean(value)
       [true, "true", "yes", 1, "1", "t"].include?(value.class == String ? value.downcase : value)
     end
+
+    def self.server_rendering_is_enabled?
+      ReactOnRails.configuration.server_bundle_js_file.present?
+    end
+
+    def self.last_process_completed_successfully?
+      $CHILD_STATUS.exitstatus == 0
+    end
   end
 end
diff --git a/lib/react_on_rails/webpack_assets_status_checker.rb b/lib/react_on_rails/webpack_assets_status_checker.rb
index 6815f1ec05..e7159dd2aa 100644
--- a/lib/react_on_rails/webpack_assets_status_checker.rb
+++ b/lib/react_on_rails/webpack_assets_status_checker.rb
@@ -17,11 +17,11 @@ def up_to_date?
     private
 
     def all_compiled_assets
-      @all_compiled_assets ||= make_file_list(make_globs(compiled_dirs)).to_ary
+      @all_compiled_assets = make_file_list(make_globs(compiled_dirs)).to_ary
     end
 
     def client_files
-      @client_files ||= make_file_list(make_globs(client_dir)).to_ary
+      @client_files = make_file_list(make_globs(client_dir)).to_ary
     end
 
     def make_globs(dirs)
diff --git a/spec/dummy/Gemfile.lock b/spec/dummy/Gemfile.lock
index 98eeac94e0..d2abc5551a 100644
--- a/spec/dummy/Gemfile.lock
+++ b/spec/dummy/Gemfile.lock
@@ -4,6 +4,7 @@ PATH
     react_on_rails (2.3.0)
       connection_pool
       execjs (~> 2.5)
+      foreman
       rails (>= 3.2)
       rainbow (~> 2.1)
 
@@ -105,6 +106,8 @@ GEM
     erubis (2.7.0)
     execjs (2.6.0)
     ffi (1.9.10)
+    foreman (0.78.0)
+      thor (~> 0.19.1)
     generator_spec (0.9.3)
       activesupport (>= 3.0.0)
       railties (>= 3.0.0)
diff --git a/spec/dummy/Procfile.spec b/spec/dummy/Procfile.spec
new file mode 100644
index 0000000000..2c2700a290
--- /dev/null
+++ b/spec/dummy/Procfile.spec
@@ -0,0 +1,2 @@
+client-static-assets: sh -c 'rm app/assets/javascripts/generated/* || true && cd client && npm run build:dev:client'
+server-static-assets: sh -c 'cd client && npm run build:dev:server'
diff --git a/spec/react_on_rails/ensure_assets_compiled_spec.rb b/spec/react_on_rails/ensure_assets_compiled_spec.rb
index 095e607307..a7cdb96f9b 100644
--- a/spec/react_on_rails/ensure_assets_compiled_spec.rb
+++ b/spec/react_on_rails/ensure_assets_compiled_spec.rb
@@ -1,41 +1,61 @@
 require_relative "simplecov_helper"
 require_relative "spec_helper"
 
-class WebpackAssetsCompilerDouble
-  attr_reader :times_ran
-
-  def initialize
-    @times_ran = 0
-  end
-
-  def compile
-    @times_ran += 1
-  end
-end
-
 module ReactOnRails
   describe EnsureAssetsCompiled do
-    let(:compiler) { WebpackAssetsCompilerDouble.new }
-    let(:ensurer) { EnsureAssetsCompiled.new(checker, compiler) }
+    let(:compiler) { double_assets_compiler }
+    let(:ensurer) { EnsureAssetsCompiled.new(assets_checker, compiler, process_checker) }
 
     context "when assets are not up to date" do
-      let(:checker) { double_webpack_assets_checker(up_to_date: false) }
+      let(:assets_checker) { double_assets_checker(up_to_date: false) }
+
+      context "and webpack process is running" do
+        let(:process_checker) { double_process_checker(running: true) }
+
+        it "sleeps until assets are up to date" do
+          expect(compiler).not_to receive(:compile)
+
+          thread = Thread.new { ensurer.call }
 
-      it "compiles the webpack bundles" do
-        expect { ensurer.call }.to change { compiler.times_ran }.from(0).to(1)
+          sleep 1
+          allow(assets_checker).to receive(:up_to_date?).and_return(true)
+
+          thread.join
+
+          expect(ensurer.assets_have_been_compiled).to eq(true)
+        end
+      end
+
+      context "and webpack process is NOT running" do
+        let(:process_checker) { double_process_checker(running: false) }
+
+        it "compiles the webpack assets" do
+          expect(compiler).to receive(:compile).once
+          ensurer.call
+        end
       end
     end
 
     context "when assets are up to date" do
-      let(:checker) { double_webpack_assets_checker(up_to_date: true) }
+      let(:assets_checker) { double_assets_checker(up_to_date: true) }
+      let(:process_checker) { double_process_checker(running: false) }
 
-      it "does not compile the webpack bundles if they exist and are up to date" do
-        expect { ensurer.call }.not_to change { compiler.times_ran }
+      it "does nothing" do
+        expect(compiler).not_to receive(:compile)
+        ensurer.call
       end
     end
 
-    def double_webpack_assets_checker(args = {})
+    def double_process_checker(args = {})
+      instance_double(WebpackProcessChecker, running?: args.fetch(:running))
+    end
+
+    def double_assets_checker(args = {})
       instance_double(WebpackAssetsStatusChecker, up_to_date?: args.fetch(:up_to_date))
     end
+
+    def double_assets_compiler
+      instance_double(WebpackAssetsCompiler, :compile)
+    end
   end
 end