diff --git a/.buildlibrary b/.buildlibrary
index 9f783341..00f3d3a3 100644
--- a/.buildlibrary
+++ b/.buildlibrary
@@ -1,4 +1,4 @@
-ValidationKey: '27487080'
+ValidationKey: '27545872'
 AutocreateReadme: yes
 AcceptedWarnings:
 - 'Warning: package ''.*'' was built under R version'
diff --git a/CITATION.cff b/CITATION.cff
index 41b03d2f..a6576d9e 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: 'mrmagpie: madrat based MAgPIE Input Data Library'
-version: 1.39.5
-date-released: '2023-12-13'
+version: 1.39.6
+date-released: '2024-01-10'
 abstract: Provides functions for MAgPIE country and cellular input data generation.
 authors:
 - family-names: Karstens
diff --git a/DESCRIPTION b/DESCRIPTION
index 1e75b54e..be2b59a3 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Type: Package
 Package: mrmagpie
 Title: madrat based MAgPIE Input Data Library
-Version: 1.39.5
-Date: 2023-12-13
+Version: 1.39.6
+Date: 2024-01-10
 Authors@R: c(
     person("Kristine", "Karstens", , "karstens@pik-potsdam.de", role = c("aut", "cre")),
     person("Jan Philipp", "Dietrich", , "dietrich@pik-potsdam.de", role = "aut"),
diff --git a/R/calcClusterBase.R b/R/calcClusterBase.R
index 0556d9ea..3a3810b2 100755
--- a/R/calcClusterBase.R
+++ b/R/calcClusterBase.R
@@ -23,6 +23,9 @@ calcClusterBase <- function(clusterdata = "yield_airrig",
                            years = 1995, aggregate = FALSE)
     d$td     <- calcOutput("TransportTime", cells = "lpjcell",
                            aggregate = FALSE)[, , rep(1, floor(ndata(d$yld) / 2))]
+    gridpop <- collapseNames(calcOutput("GridPop", source = "Gao", urban = FALSE,
+                                        aggregate = FALSE, years = 1995)[, , "SSP2"])
+    d$gp  <- gridpop[, , rep(1, floor(ndata(d$yld) / 2))]
 
   } else if (clusterdata == "yield_increment") {
 
@@ -33,6 +36,9 @@ calcClusterBase <- function(clusterdata = "yield_airrig",
                  - collapseNames(yield[, , "rainfed"][, , "pasture", invert = TRUE]))
     d$td     <- calcOutput("TransportTime", cells = "lpjcell",
                            aggregate = FALSE)[, , rep(1, ndata(d$yld))]
+    gridpop <- collapseNames(calcOutput("GridPop", source = "Gao", urban = FALSE,
+                                        aggregate = FALSE, years = 1995)[, , "SSP2"])
+    d$gp  <- gridpop[, , rep(1, floor(ndata(d$yld)))]
 
   } else {
     stop("Specify clusterdata argument: yield_airrig (old clustering data)
diff --git a/README.md b/README.md
index ec0ee632..3f29947c 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # madrat based MAgPIE Input Data Library
 
-R package **mrmagpie**, version **1.39.5**
+R package **mrmagpie**, version **1.39.6**
 
 [![CRAN status](https://www.r-pkg.org/badges/version/mrmagpie)](https://cran.r-project.org/package=mrmagpie) [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.4319612.svg)](https://doi.org/10.5281/zenodo.4319612) [![R build status](https://github.com/pik-piam/mrmagpie/workflows/check/badge.svg)](https://github.com/pik-piam/mrmagpie/actions) [![codecov](https://codecov.io/gh/pik-piam/mrmagpie/branch/master/graph/badge.svg)](https://app.codecov.io/gh/pik-piam/mrmagpie) [![r-universe](https://pik-piam.r-universe.dev/badges/mrmagpie)](https://pik-piam.r-universe.dev/builds)
 
@@ -39,7 +39,7 @@ In case of questions / problems please contact Kristine Karstens <karstens@pik-p
 
 To cite package **mrmagpie** in publications use:
 
-Karstens K, Dietrich J, Chen D, Windisch M, Alves M, Beier F, Köberle A, v. Jeetze P, Mishra A, Humpenoeder F, Sauer P (2023). _mrmagpie: madrat based MAgPIE Input Data Library_. doi: 10.5281/zenodo.4319612 (URL: https://doi.org/10.5281/zenodo.4319612), R package version 1.39.5, <URL: https://github.com/pik-piam/mrmagpie>.
+Karstens K, Dietrich J, Chen D, Windisch M, Alves M, Beier F, Köberle A, v. Jeetze P, Mishra A, Humpenoeder F, Sauer P (2024). _mrmagpie: madrat based MAgPIE Input Data Library_. doi: 10.5281/zenodo.4319612 (URL: https://doi.org/10.5281/zenodo.4319612), R package version 1.39.6, <URL: https://github.com/pik-piam/mrmagpie>.
 
 A BibTeX entry for LaTeX users is
 
@@ -47,8 +47,8 @@ A BibTeX entry for LaTeX users is
 @Manual{,
   title = {mrmagpie: madrat based MAgPIE Input Data Library},
   author = {Kristine Karstens and Jan Philipp Dietrich and David Chen and Michael Windisch and Marcos Alves and Felicitas Beier and Alexandre Köberle and Patrick {v. Jeetze} and Abhijeet Mishra and Florian Humpenoeder and Pascal Sauer},
-  year = {2023},
-  note = {R package version 1.39.5},
+  year = {2024},
+  note = {R package version 1.39.6},
   doi = {10.5281/zenodo.4319612},
   url = {https://github.com/pik-piam/mrmagpie},
 }