diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index de567544b..c8228b36f 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -172,7 +172,7 @@ BootstrapDebCommon() {
   # distro version (#346)
 
   virtualenv=
-  if apt-cache show virtualenv > /dev/null 2>&1; then
+  if apt-cache show virtualenv > /dev/null 2>&1 && ! apt-cache --quiet=0 show virtualenv 2>&1 | grep -q 'No packages found'; then
     virtualenv="virtualenv"
   fi
 
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh
index bfbcfa31d..8eb7e16ee 100644
--- a/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh
@@ -23,7 +23,7 @@ BootstrapDebCommon() {
   # distro version (#346)
 
   virtualenv=
-  if apt-cache show virtualenv > /dev/null 2>&1; then
+  if apt-cache show virtualenv > /dev/null 2>&1 && ! apt-cache --quiet=0 show virtualenv 2>&1 | grep -q 'No packages found'; then
     virtualenv="virtualenv"
   fi