diff --git a/pavelib/prereqs.py b/pavelib/prereqs.py
index 60766bb1ac..014a23e3e5 100644
--- a/pavelib/prereqs.py
+++ b/pavelib/prereqs.py
@@ -85,20 +85,22 @@ def prereq_cache(cache_name, paths, install_func):
                 raise
 
         with open(cache_file_path, "w") as cache_file:
-            cache_file.write(new_hash)
-
+            # Since the pip requirement files are modified during the install
+            # process, we need to store the hash generated AFTER the installation
+            post_install_hash = compute_fingerprint(paths)
+            cache_file.write(post_install_hash)
     else:
         print('{cache} unchanged, skipping...'.format(cache=cache_name))
 
 
-def install_ruby_prereqs():
+def ruby_prereqs_installation():
     """
     Installs Ruby prereqs
     """
     sh('bundle install --quiet')
 
 
-def install_node_prereqs():
+def node_prereqs_installation():
     """
     Installs Node prerequisites
     """
@@ -106,8 +108,7 @@ def install_node_prereqs():
     sh('npm install')
 
 
-@task
-def install_python_prereqs():
+def python_prereqs_installation():
     """
     Installs Python prerequisites
     """
@@ -115,6 +116,30 @@ def install_python_prereqs():
         sh("pip install -q --exists-action w -r {req_file}".format(req_file=req_file))
 
 
+@task
+def install_ruby_prereqs():
+    """
+    Installs Ruby prereqs
+    """
+    prereq_cache("Ruby prereqs", ["Gemfile"], ruby_prereqs_installation)
+
+
+@task
+def install_node_prereqs():
+    """
+    Installs Node prerequisites
+    """
+    prereq_cache("Node prereqs", ["package.json"], node_prereqs_installation)
+
+
+@task
+def install_python_prereqs():
+    """
+    Installs Python prerequisites
+    """
+    prereq_cache("Python prereqs", PYTHON_REQ_FILES + [sysconfig.get_python_lib()], python_prereqs_installation)
+
+
 @task
 def install_prereqs():
     """
@@ -123,6 +148,6 @@ def install_prereqs():
     if os.environ.get("NO_PREREQ_INSTALL", False):
         return
 
-    prereq_cache("Ruby prereqs", ["Gemfile"], install_ruby_prereqs)
-    prereq_cache("Node prereqs", ["package.json"], install_node_prereqs)
-    prereq_cache("Python prereqs", PYTHON_REQ_FILES + [sysconfig.get_python_lib()], install_python_prereqs)
+    install_ruby_prereqs()
+    install_node_prereqs()
+    install_python_prereqs()
diff --git a/rakelib/js_test.rake b/rakelib/js_test.rake
index 361129a19c..3e15d43e8c 100644
--- a/rakelib/js_test.rake
+++ b/rakelib/js_test.rake
@@ -60,7 +60,7 @@ end
 namespace :'test:js' do
 
     desc "Run the JavaScript tests and print results to the console"
-    task :run, [:env] => [:clean_test_files, JS_REPORT_DIR] do |t, args|
+    task :run, [:env] => [:clean_test_files, JS_REPORT_DIR, :install_node_prereqs] do |t, args|
         compile_coffeescript()
 
         if args[:env].nil?
@@ -71,7 +71,7 @@ namespace :'test:js' do
     end
 
     desc "Run the JavaScript tests in your default browser"
-    task :dev, [:env] => [:clean_test_files] do |t, args|
+    task :dev, [:env] => [:clean_test_files, :install_node_prereqs] do |t, args|
         compile_coffeescript()
 
         if args[:env].nil?
@@ -83,7 +83,7 @@ namespace :'test:js' do
     end
 
     desc "Run all JavaScript tests and collect coverage information"
-    task :coverage => [:clean_reports_dir, :clean_test_files, JS_REPORT_DIR] do
+    task :coverage => [:clean_reports_dir, :clean_test_files, JS_REPORT_DIR, :install_node_prereqs] do
         compile_coffeescript()
         js_test_tool(nil, 'run', true)
     end
diff --git a/rakelib/prereqs_deprecated.rake b/rakelib/prereqs_deprecated.rake
index 8f9a8f5154..57701c150c 100644
--- a/rakelib/prereqs_deprecated.rake
+++ b/rakelib/prereqs_deprecated.rake
@@ -15,7 +15,7 @@ def deprecated(deprecated, deprecated_by)
 end
 
 deprecated('install_prereqs','paver install_prereqs')
-deprecated('install_node_prereqs','paver install_prereqs')
-deprecated('install_ruby_prereqs','paver install_prereqs')
-deprecated('install_python_prereqs','paver install_prereqs')
+deprecated('install_node_prereqs','paver install_node_prereqs')
+deprecated('install_ruby_prereqs','paver install_ruby_prereqs')
+deprecated('install_python_prereqs','paver install_python_prereqs')