diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 7546e5217..e289f8239 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -95,7 +95,8 @@ jobs:
                 if [ "${USE_SCIPY}" == "1" ]; then pip install ${SCIPY_MIN}; fi
             elif [ "${OPTIONS_NAME}" == "editable-install" ]; then
                 echo "Testing an editable install of pywt"
-                pip install numpy==1.26.0 cython meson-python matplotlib pytest
+                pip install numpy==1.26.0 cython meson-python ninja matplotlib pytest
+                # should we do apt-get install ninja instead and use a system ninja instead?
                 pip install -e . --no-build-isolation
             else
                 pip install ${PIP_FLAGS} cython
diff --git a/pyproject.toml b/pyproject.toml
index b49eac72c..4f34cb17f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,6 +9,7 @@ build-backend = "mesonpy"
 requires = [
     "meson-python>=0.14.0",
     "Cython>=0.29.35",
+    "ninja>=1.10.0",
 
     # When numpy 2.0.0rc1 comes out, we should update this to build against 2.0,
     # and then runtime depend on the range 1.22.X to <2.3. No need to switch to