diff --git a/.crow/build-all-versions.yaml b/.crow/build-all-versions.yaml
index fb1229d..39a8075 100644
--- a/.crow/build-all-versions.yaml
+++ b/.crow/build-all-versions.yaml
@@ -36,7 +36,13 @@ variables:
     default: '3.24'
   R_VERSION:
     description: 'Primary R version under /opt/R.'
+    # The supported window is latest plus the two previous, which the build
+    # images install as R_VERSION_LATEST/PREV1/PREV2. 4.6.0 was missing here,
+    # so no pipeline could run the per-minor pass for it and its slots kept a
+    # backlog: rlang exists for 4.4 and 4.5 on amd64/resolute but not 4.6,
+    # which is how an R 4.6.1 client ended up loading a 4.5.3 binary.
     options:
+      - 4.6.0
       - 4.5.3
       - 4.4.3
     default: 4.5.3