diff --git a/.buildlibrary b/.buildlibrary
index b977d143..4b918366 100644
--- a/.buildlibrary
+++ b/.buildlibrary
@@ -1,4 +1,4 @@
-ValidationKey: '121782300'
+ValidationKey: '122048142'
 AcceptedWarnings:
 - 'Warning: package ''.*'' was built under R version'
 - 'Warning: namespace ''.*'' is not available and has been replaced'
diff --git a/.github/workflows/check.yaml b/.github/workflows/check.yaml
index 46f518a2..f6ea5d40 100644
--- a/.github/workflows/check.yaml
+++ b/.github/workflows/check.yaml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: r-lib/actions/setup-pandoc@v2
 
@@ -23,7 +23,6 @@ jobs:
       - uses: r-lib/actions/setup-r-dependencies@v2
         with:
           extra-packages: |
-            gamstransfer=?ignore
             any::lucode2
             any::covr
             any::madrat
@@ -36,7 +35,7 @@ jobs:
           # gms, goxygen, GDPuc) will usually have an outdated binary version
           # available; by using extra-packages we get the newest version
 
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: 3.9
 
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 243f46a1..62f13da6 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,7 +3,7 @@
 exclude: '^tests/testthat/_snaps/.*$'
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.5.0
+    rev: 2c9f875913ee60ca25ce70243dc24d5b6415598c  # frozen: v4.6.0
     hooks:
     -   id: check-case-conflict
     -   id: check-json
@@ -15,7 +15,7 @@ repos:
     -   id: mixed-line-ending
 
 -   repo: https://github.com/lorenzwalthert/precommit
-    rev: v0.4.0
+    rev: 7910e0323d7213f34275a7a562b9ef0fde8ce1b9  # frozen: v0.4.2
     hooks:
     -   id: parsable-R
     -   id: deps-in-desc
diff --git a/CITATION.cff b/CITATION.cff
index 254847eb..abad4ad2 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -2,8 +2,8 @@ cff-version: 1.2.0
 message: If you use this software, please cite it using the metadata from this file.
 type: software
 title: 'magclass: Data Class and Tools for Handling Spatial-Temporal Data'
-version: 6.15.0
-date-released: '2024-03-20'
+version: 6.15.1
+date-released: '2024-04-29'
 abstract: Data class for increased interoperability working with spatial-temporal
   data together with corresponding functions and methods (conversions, basic calculations
   and basic data manipulation). The class distinguishes between spatial, temporal
diff --git a/DESCRIPTION b/DESCRIPTION
index 181ae995..22b1bf48 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Type: Package
 Package: magclass
 Title: Data Class and Tools for Handling Spatial-Temporal Data
-Version: 6.15.0
-Date: 2024-03-20
+Version: 6.15.1
+Date: 2024-04-29
 Authors@R: c(
     person("Jan Philipp", "Dietrich", , "dietrich@pik-potsdam.de", role = c("aut", "cre")),
     person("Benjamin Leon", "Bodirsky", , "bodirsky@pik-potsdam.de", role = "aut"),
diff --git a/R/writeNC.R b/R/writeNC.R
index 0cca3b0a..8238dfea 100644
--- a/R/writeNC.R
+++ b/R/writeNC.R
@@ -39,6 +39,9 @@ writeNC <- function(x, filename, unit, ..., compression = 2, missval = NA,
     firstY <- gridDefinition[4]
     lastY <- gridDefinition[3]
     res <- gridDefinition[5]
+    # swap y values before passing gridDefinition to magclass::extend
+    gridDefinition[3] <- firstY
+    gridDefinition[4] <- lastY
   }
   xCoords <- seq(firstX, lastX, res)
   yCoords <- seq(firstY, lastY, -res)
diff --git a/README.md b/README.md
index fd0cb0c6..1497814b 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Data Class and Tools for Handling Spatial-Temporal Data
 
-R package **magclass**, version **6.15.0**
+R package **magclass**, version **6.15.1**
 
 [![CRAN status](https://www.r-pkg.org/badges/version/magclass)](https://cran.r-project.org/package=magclass) [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.1158580.svg)](https://doi.org/10.5281/zenodo.1158580) [![R build status](https://github.com/pik-piam/magclass/workflows/check/badge.svg)](https://github.com/pik-piam/magclass/actions) [![codecov](https://codecov.io/gh/pik-piam/magclass/branch/master/graph/badge.svg)](https://app.codecov.io/gh/pik-piam/magclass) [![r-universe](https://pik-piam.r-universe.dev/badges/magclass)](https://pik-piam.r-universe.dev/builds)
 
@@ -56,7 +56,7 @@ In case of questions / problems please contact Jan Philipp Dietrich <dietrich@pi
 
 To cite package **magclass** in publications use:
 
-Dietrich J, Bodirsky B, Bonsch M, Humpenoeder F, Bi S, Karstens K, Leip D, Sauer P (2024). _magclass: Data Class and Tools for Handling Spatial-Temporal Data_. doi:10.5281/zenodo.1158580 <https://doi.org/10.5281/zenodo.1158580>, R package version 6.15.0, <https://github.com/pik-piam/magclass>.
+Dietrich J, Bodirsky B, Bonsch M, Humpenoeder F, Bi S, Karstens K, Leip D, Sauer P (2024). _magclass: Data Class and Tools for Handling Spatial-Temporal Data_. doi:10.5281/zenodo.1158580 <https://doi.org/10.5281/zenodo.1158580>, R package version 6.15.1, <https://github.com/pik-piam/magclass>.
 
 A BibTeX entry for LaTeX users is
 
@@ -65,7 +65,7 @@ A BibTeX entry for LaTeX users is
   title = {magclass: Data Class and Tools for Handling Spatial-Temporal Data},
   author = {Jan Philipp Dietrich and Benjamin Leon Bodirsky and Markus Bonsch and Florian Humpenoeder and Stephen Bi and Kristine Karstens and Debbora Leip and Pascal Sauer},
   year = {2024},
-  note = {R package version 6.15.0},
+  note = {R package version 6.15.1},
   url = {https://github.com/pik-piam/magclass},
   doi = {10.5281/zenodo.1158580},
 }