diff --git a/changelog.d/rpkg-ci-pandoc.fixed.md b/changelog.d/rpkg-ci-pandoc.fixed.md
new file mode 100644
index 000000000..51b8af76f
--- /dev/null
+++ b/changelog.d/rpkg-ci-pandoc.fixed.md
@@ -0,0 +1,2 @@
+- `condor-batch/image/rpkg-ci.def`: sets `RSTUDIO_PANDOC` to Quarto's bundled pandoc, so `R CMD build` can build R Markdown vignettes inside the image.
+  A cold `R CMD check` of rampp on a cluster node failed with "Pandoc is required to build R Markdown vignettes" until the variable was set by hand (gha#1640).
diff --git a/condor-batch/image/rpkg-ci.def b/condor-batch/image/rpkg-ci.def
index c7f90fd68..0dfce5d6e 100644
--- a/condor-batch/image/rpkg-ci.def
+++ b/condor-batch/image/rpkg-ci.def
@@ -2,7 +2,7 @@ Bootstrap: localimage
 From: lds-ci.sif
 
 # R-package CI image for condor-batch (gha#1640): R CMD check, covr and pkgdown
-# on a cluster execute node. Built from lds-ci.sif so it shares R 4.5, Quarto and
+# on a cluster execute node. Built from lds-ci.sif so it shares R, Quarto and
 # TinyTeX. It adds the tools the r-lib workflows install and the system libraries
 # the commonest package dependencies compile against.
 #
@@ -20,6 +20,8 @@ From: lds-ci.sif
     export R_LIBS_USER=${PWD}/.rlib
     export R_REPOS_PPM="https://packagemanager.posit.co/cran/__linux__/noble/latest"
     export _R_CHECK_FORCE_SUGGESTS_=false
+    # Quarto bundles pandoc off PATH; R CMD build needs it to build R Markdown vignettes.
+    export RSTUDIO_PANDOC=/opt/quarto/bin/tools/x86_64
 
 %post
     set -eux