diff --git a/requirements.txt b/requirements.txt
index 0861ac0..be5d6d3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 colour
+numpy
 pillow
diff --git a/setup.py b/setup.py
index 0976e7a..04b0bcf 100644
--- a/setup.py
+++ b/setup.py
@@ -17,5 +17,5 @@ setup(
     license="LICENSE",
     description="A colorful wallpaper generator",
     long_description=open("README.org").read(),
-    install_requires=["colour", "pillow"],
+    install_requires=["colour", "numpy", "pillow"],
 )