diff --git a/poetry.lock b/poetry.lock
index 20340fca..f43acd93 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -454,7 +454,7 @@ mccabe = ">=0.6,<0.7"
 toml = ">=0.7.1"
 
 [[package]]
-category = "main"
+category = "dev"
 description = "Python interface to your NPM and package.json."
 name = "pynpm"
 optional = false
@@ -760,7 +760,7 @@ ifaddr = "*"
 rpi = ["RPi.GPIO"]
 
 [metadata]
-content-hash = "e62efd90867a69b3385fb417a0cd0a9124fb4d23a36177ebef27903b4e78eb77"
+content-hash = "8874534b3ed4146a2da1884b8f69b639b4a06f41ab9d6ee17500513b2d76f1b9"
 python-versions = "^3.6"
 
 [metadata.files]
diff --git a/pyproject.toml b/pyproject.toml
index d9d6e9b1..f189b194 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,7 +47,6 @@ opencv-python-headless = [
     {version = "4.2.0.34", python = "^3.8"}  # Latest for Py38 systems
 ]
 labthings = "0.6.1"
-pynpm = "^0.1.2"
 
 [tool.poetry.extras]
 rpi = ["RPi.GPIO"]
@@ -56,6 +55,7 @@ rpi = ["RPi.GPIO"]
 build_static = 'openflexure_microscope.install:build'
 
 [tool.poetry.dev-dependencies]
+pynpm = "^0.1.2"
 sphinxcontrib-httpdomain = "^1.7"
 rope = "^0.14.0"
 pylint = "^2.3"