diff --git a/.buildlibrary b/.buildlibrary
index 4d76417..0c4db78 100644
--- a/.buildlibrary
+++ b/.buildlibrary
@@ -1,4 +1,4 @@
-ValidationKey: '8013200'
+ValidationKey: '8033634'
 AutocreateReadme: yes
 AcceptedWarnings:
 - 'Warning: package ''.*'' was built under R version'
diff --git a/CITATION.cff b/CITATION.cff
index 4460715..cabbe42 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: 'mrdrivers: Create GDP and Population Scenarios'
-version: 4.0.0
-date-released: '2024-11-06'
+version: 4.0.1
+date-released: '2024-11-07'
 abstract: Create GDP and population scenarios This package constructs the GDP and
   population scenarios used as drivers in both the REMIND and MAgPIE models.
 authors:
diff --git a/DESCRIPTION b/DESCRIPTION
index 9c232b5..58dafe6 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: mrdrivers
 Type: Package
 Title: Create GDP and Population Scenarios
-Version: 4.0.0
+Version: 4.0.1
 Authors@R: c(person(given = "Johannes", 
                     family = "Koch", 
                     email = "jokoch@pik-potsdam.de", 
@@ -44,6 +44,6 @@ Suggests:
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.3.2
-Date: 2024-11-06
+Date: 2024-11-07
 Config/testthat/edition: 3
 VignetteBuilder: knitr
diff --git a/R/calcGDPPast.R b/R/calcGDPPast.R
index 3792da3..406fbb1 100644
--- a/R/calcGDPPast.R
+++ b/R/calcGDPPast.R
@@ -34,9 +34,11 @@ calcGDPPast <- function(pastData = "WDI-MI-James", extension1960 = "MI-James") {
                             aggregate = FALSE,
                             supplementary = TRUE)
     data <- toolHarmonizeFuture(past = data1960, future = data, method = "growth")
-    data$x <- toolInterpolateAndExtrapolate(data$x)
   }
 
+  # Fill in trailing zeros with closest value
+  data$x <- toolInterpolateAndExtrapolate(data$x)
+
   list(x = data$x,
        weight = NULL,
        unit = glue("mil. {toolGetUnitDollar(inPPP = TRUE)}"),
diff --git a/R/calcPopulationPast.R b/R/calcPopulationPast.R
index 69dfbcb..011102c 100644
--- a/R/calcPopulationPast.R
+++ b/R/calcPopulationPast.R
@@ -4,9 +4,13 @@ calcPopulationPast <- function(pastData = "WDI-UN_PopDiv-MI") {
   toolCheckUserInput("PopulationPast", as.list(environment()))
   # Call calcInternalPopulationPast function the appropriate number of times (map) and combine (reduce)
   # !! Keep formula syntax for madrat caching to work
-  purrr::pmap(list("pastData" = unlist(strsplit(pastData, "-"))),
-              ~calcOutput("InternalPopulationPast", aggregate = FALSE, supplementary = TRUE, ...)) %>%
+  data <- purrr::pmap(list("pastData" = unlist(strsplit(pastData, "-"))),
+                      ~calcOutput("InternalPopulationPast", aggregate = FALSE, supplementary = TRUE, ...)) %>%
     toolListFillWith()
+
+  # Fill in trailing zeros with closest value
+  data$x <- toolInterpolateAndExtrapolate(data$x)
+  data
 }
 
 calcInternalPopulationPast <- function(pastData) {
diff --git a/README.md b/README.md
index 03d79ce..58fde0f 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Create GDP and Population Scenarios
 
-R package **mrdrivers**, version **4.0.0**
+R package **mrdrivers**, version **4.0.1**
 
 [![CRAN status](https://www.r-pkg.org/badges/version/mrdrivers)](https://cran.r-project.org/package=mrdrivers)  [![R build status](https://pik-piam.github.io/mrdrivers/workflows/check/badge.svg)](https://pik-piam.github.io/mrdrivers/actions) [![codecov](https://codecov.io/gh/mrdrivers/branch/master/graph/badge.svg)](https://app.codecov.io/gh/mrdrivers) [![r-universe](https://pik-piam.r-universe.dev/badges/mrdrivers)](https://pik-piam.r-universe.dev/builds)
 
@@ -100,7 +100,7 @@ In case of questions / problems please contact Johannes Koch <jokoch@pik-potsdam
 
 To cite package **mrdrivers** in publications use:
 
-Koch J, Soergel B, Leip D, Benke F, Dietrich J (2024). _mrdrivers: Create GDP and Population Scenarios_. R package version 4.0.0, <https://pik-piam.github.io/mrdrivershttps://github.com/pik-piam/mrdrivers>.
+Koch J, Soergel B, Leip D, Benke F, Dietrich J (2024). _mrdrivers: Create GDP and Population Scenarios_. R package version 4.0.1, <https://pik-piam.github.io/mrdrivershttps://github.com/pik-piam/mrdrivers>.
 
 A BibTeX entry for LaTeX users is
 
@@ -109,7 +109,7 @@ A BibTeX entry for LaTeX users is
   title = {mrdrivers: Create GDP and Population Scenarios},
   author = {Johannes Koch and Bjoern Soergel and Deborra Leip and Falk Benke and Jan Philipp Dietrich},
   year = {2024},
-  note = {R package version 4.0.0},
+  note = {R package version 4.0.1},
   url = {https://pik-piam.github.io/mrdrivers},
   url = {https://github.com/pik-piam/mrdrivers},
 }