diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a5186896a..57605e28b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -77,6 +77,7 @@ jobs:
       - uses: prefix-dev/setup-pixi@v0.9.0
         with:
           pixi-version: ${{ needs.cache-pixi-lock.outputs.pixi-version }}
+          locked: false # TODO: Remove once v7 of the lock file is removed, or once we stop having external source dependencies https://github.com/Parcels-code/Parcels/pull/2550#issuecomment-4088660238
           cache: true
           cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#update-a-cache
@@ -137,6 +138,7 @@ jobs:
       - uses: prefix-dev/setup-pixi@v0.9.0
         with:
           pixi-version: ${{ needs.cache-pixi-lock.outputs.pixi-version }}
+          locked: false # TODO: Remove once v7 of the lock file is removed, or once we stop having external source dependencies https://github.com/Parcels-code/Parcels/pull/2550#issuecomment-4088660238
           cache: true
           cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       - name: Integration test
@@ -180,6 +182,7 @@ jobs:
       - uses: prefix-dev/setup-pixi@v0.9.0
         with:
           pixi-version: ${{ needs.cache-pixi-lock.outputs.pixi-version }}
+          locked: false # TODO: Remove once v7 of the lock file is removed, or once we stop having external source dependencies https://github.com/Parcels-code/Parcels/pull/2550#issuecomment-4088660238
           cache: true
           cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       - name: Typechecking
@@ -202,6 +205,7 @@ jobs:
       - uses: prefix-dev/setup-pixi@v0.9.0
         with:
           pixi-version: ${{ needs.cache-pixi-lock.outputs.pixi-version }}
+          locked: false # TODO: Remove once v7 of the lock file is removed, or once we stop having external source dependencies https://github.com/Parcels-code/Parcels/pull/2550#issuecomment-4088660238
           cache: true
           cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       - name: Find the alpha version of Parcels
diff --git a/pixi.toml b/pixi.toml
index 1e24524a9..f0d226fed 100644
--- a/pixi.toml
+++ b/pixi.toml
@@ -27,7 +27,7 @@ holoviews = ">=1.22.0" # https://github.com/prefix-dev/rattler-build/issues/2326
 uxarray = ">=2025.3.0"
 dask = ">=2024.5.1"
 zarr = ">=2.15.0,!=2.18.0,<3"
-xgcm = ">=0.9.0"
+xgcm = { git = "https://github.com/veckoTheGecko/xgcm", rev = "import" } # TODO Switch to main when import improvements are merged
 cf_xarray = ">=0.8.6"
 cftime = ">=1.6.3"
 pooch = ">=1.8.0"
@@ -54,7 +54,7 @@ xarray = "2024.5.*"
 uxarray = "2025.3.*"
 dask = "2024.5.*"
 zarr = "2.15.*"
-xgcm = "0.9.*"
+xgcm = { version = "0.9.*", channel = "conda-forge" }
 cf_xarray = "0.8.*"
 cftime = "1.6.*"
 pooch = "1.8.*"
@@ -102,6 +102,9 @@ memray = "*"
 [feature.devtools.target.osx-arm64.dependencies]
 memray = "*"
 
+[feature.devtools.pypi-dependencies]
+tuna = ">=0.5.11"
+
 [feature.docs.dependencies]
 parcels = { path = "." }
 numpydoc = "*"