diff --git a/.gitignore b/.gitignore
index 6a5b616..0896862 100644
--- a/.gitignore
+++ b/.gitignore
@@ -133,3 +133,6 @@ dmypy.json
 
 # Pyre type checker
 .pyre/
+
+# macOS
+.DS_Store
diff --git a/requirements.txt b/requirements.txt
index 13d832c..62b5b13 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
-numpy>=1.9.3
+numpy>=1.17
+duecredit