diff --git a/requirements.txt b/requirements.txt
index 1886fb050..1f41a9313 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,4 @@ murmurhash
 unidecode
 numpy
 wget
+plac
diff --git a/setup.py b/setup.py
index a145f119d..7c7c6a0d3 100644
--- a/setup.py
+++ b/setup.py
@@ -103,7 +103,7 @@ def run_setup(exts):
         ext_modules=exts,
         license="Dual: Commercial or AGPL",
         install_requires=['numpy', 'murmurhash', 'cymem', 'preshed', 'thinc',
-                          "unidecode", 'wget'],
+                          "unidecode", 'wget', 'plac'],
         setup_requires=["headers_workaround"],
     )