diff --git a/requirements.txt b/requirements.txt
index d490aee8b..bd606d8e4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
-# Just matplotlib :)
+# Just matplotlib and numpy :)
 matplotlib>=3.0.0
+numpy
diff --git a/setup.cfg b/setup.cfg
index a30e3693b..8b422f223 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,6 +27,8 @@ project_urls =
 
 [options]
 packages = proplot
-install_requires = matplotlib>=3.0.0,<3.6.0
+install_requires =
+    matplotlib>=3.0.0,<3.6.0
+    numpy
 include_package_data = True
 python_requires = >=3.6.0