diff --git a/Documentation/sphinx/requirements.txt b/Documentation/sphinx/requirements.txt
new file mode 100644
index 0000000..742be3e
--- /dev/null
+++ b/Documentation/sphinx/requirements.txt
@@ -0,0 +1,3 @@
+docutils==0.12
+Sphinx==1.4.9
+sphinx_rtd_theme
diff --git a/scripts/sphinx-pre-install b/scripts/sphinx-pre-install
index bcd6f79..230d9cc 100755
--- a/scripts/sphinx-pre-install
+++ b/scripts/sphinx-pre-install
@@ -14,6 +14,7 @@
 # GNU General Public License for more details.
 
 my $virtenv_dir = "sphinx_1.4";
+my $requirement_file = "Documentation/sphinx/requirements.txt";
 
 #
 # Static vars
@@ -467,9 +468,7 @@
 
 			printf "\t$virtualenv $virtenv_dir\n";
 			printf "\t. $activate\n";
-			printf "\tpip install 'docutils==0.12'\n";
-			printf "\tpip install 'Sphinx==1.4.9'\n";
-			printf "\tpip install sphinx_rtd_theme\n";
+			printf "\tpip install -r $requirement_file\n";
 			$need++;
 		}
 	}