diff --git a/.buildkite/hooks/pre-command b/.buildkite/hooks/pre-command
index bed5503fa5..57fa49f852 100644
--- a/.buildkite/hooks/pre-command
+++ b/.buildkite/hooks/pre-command
@@ -7,6 +7,16 @@
 #
 (
   d=$HOME/cargo-target-cache/"$CARGO_TARGET_CACHE_NAME"
+
+  if [[ -d $d ]]; then
+    du -hs "$d"
+    read -r cacheSizeInGB _ < <(du -s --block-size=1000000000 "$d")
+    if [[ $cacheSizeInGB -gt 5 ]]; then
+      echo "$d has gotten too large, removing it"
+      rm -rf "$d"
+    fi
+  fi
+
   mkdir -p "$d"/target
   set -x
   rsync -a --delete --link-dest="$d" "$d"/target .