diff --git a/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh
index 4b1e3b545..86a1ec7d6 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh
@@ -8,15 +8,20 @@ BootstrapGentooCommon() {
     app-misc/ca-certificates
     virtual/pkgconfig"
 
+  ASK_OPTION="--ask"
+  if [ "$ASSUME_YES" = 1 ]; then
+    ASK_OPTION=""
+  fi
+
   case "$PACKAGE_MANAGER" in
     (paludis)
       $SUDO cave resolve --preserve-world --keep-targets if-possible $PACKAGES -x
       ;;
     (pkgcore)
-      $SUDO pmerge --noreplace --oneshot $PACKAGES
+      $SUDO pmerge --noreplace --oneshot $ASK_OPTION $PACKAGES
       ;;
     (portage|*)
-      $SUDO emerge --noreplace --oneshot $PACKAGES
+      $SUDO emerge --noreplace --oneshot $ASK_OPTION $PACKAGES
       ;;
   esac
 }