diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index a184c5e3e..3a7421deb 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -246,10 +246,14 @@ DeprecationBootstrap() {
   fi
 }
 
+MIN_PYTHON_VERSION="2.6"
+MIN_PYVER=$(echo "$MIN_PYTHON_VERSION" | sed 's/\.//')
 # Sets LE_PYTHON to Python version string and PYVER to the first two
 # digits of the python version
 DeterminePythonVersion() {
   # Arguments: "NOCRASH" if we shouldn't crash if we don't find a good python
+  #
+  # If no Python is found, PYVER is set to 0.
   if [ -n "$USE_PYTHON_3" ]; then
     for LE_PYTHON in "$LE_PYTHON" python3; do
       # Break (while keeping the LE_PYTHON value) if found.
@@ -273,10 +277,12 @@ DeterminePythonVersion() {
   export LE_PYTHON
 
   PYVER=`"$LE_PYTHON" -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//'`
-  if [ "$PYVER" -lt 26 ]; then
-    error "You have an ancient version of Python entombed in your operating system..."
-    error "This isn't going to work; you'll need at least version 2.6."
-    exit 1
+  if [ "$PYVER" -lt "$MIN_PYVER" ]; then
+    if [ "$1" != "NOCRASH" ]; then
+      error "You have an ancient version of Python entombed in your operating system..."
+      error "This isn't going to work; you'll need at least version $MIN_PYTHON_VERSION."
+      exit 1
+    fi
   fi
 }
 
@@ -1584,8 +1590,10 @@ if __name__ == '__main__':
 
 UNLIKELY_EOF
     # ---------------------------------------------------------------------------
-    DeterminePythonVersion
-    if ! REMOTE_VERSION=`"$LE_PYTHON" "$TEMP_DIR/fetch.py" --latest-version` ; then
+    DeterminePythonVersion "NOCRASH"
+    if [ "$PYVER" -lt "$MIN_PYVER" ]; then
+      error "WARNING: couldn't find Python $MIN_PYTHON_VERSION+ to check for updates."
+    elif ! REMOTE_VERSION=`"$LE_PYTHON" "$TEMP_DIR/fetch.py" --latest-version` ; then
       error "WARNING: unable to check for updates."
     elif [ "$LE_AUTO_VERSION" != "$REMOTE_VERSION" ]; then
       say "Upgrading certbot-auto $LE_AUTO_VERSION to $REMOTE_VERSION..."
diff --git a/letsencrypt-auto-source/letsencrypt-auto.template b/letsencrypt-auto-source/letsencrypt-auto.template
index c8c5ca5c5..950fe337f 100755
--- a/letsencrypt-auto-source/letsencrypt-auto.template
+++ b/letsencrypt-auto-source/letsencrypt-auto.template
@@ -246,10 +246,14 @@ DeprecationBootstrap() {
   fi
 }
 
+MIN_PYTHON_VERSION="2.6"
+MIN_PYVER=$(echo "$MIN_PYTHON_VERSION" | sed 's/\.//')
 # Sets LE_PYTHON to Python version string and PYVER to the first two
 # digits of the python version
 DeterminePythonVersion() {
   # Arguments: "NOCRASH" if we shouldn't crash if we don't find a good python
+  #
+  # If no Python is found, PYVER is set to 0.
   if [ -n "$USE_PYTHON_3" ]; then
     for LE_PYTHON in "$LE_PYTHON" python3; do
       # Break (while keeping the LE_PYTHON value) if found.
@@ -273,10 +277,12 @@ DeterminePythonVersion() {
   export LE_PYTHON
 
   PYVER=`"$LE_PYTHON" -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//'`
-  if [ "$PYVER" -lt 26 ]; then
-    error "You have an ancient version of Python entombed in your operating system..."
-    error "This isn't going to work; you'll need at least version 2.6."
-    exit 1
+  if [ "$PYVER" -lt "$MIN_PYVER" ]; then
+    if [ "$1" != "NOCRASH" ]; then
+      error "You have an ancient version of Python entombed in your operating system..."
+      error "This isn't going to work; you'll need at least version $MIN_PYTHON_VERSION."
+      exit 1
+    fi
   fi
 }
 
@@ -595,8 +601,10 @@ else
 {{ fetch.py }}
 UNLIKELY_EOF
     # ---------------------------------------------------------------------------
-    DeterminePythonVersion
-    if ! REMOTE_VERSION=`"$LE_PYTHON" "$TEMP_DIR/fetch.py" --latest-version` ; then
+    DeterminePythonVersion "NOCRASH"
+    if [ "$PYVER" -lt "$MIN_PYVER" ]; then
+      error "WARNING: couldn't find Python $MIN_PYTHON_VERSION+ to check for updates."
+    elif ! REMOTE_VERSION=`"$LE_PYTHON" "$TEMP_DIR/fetch.py" --latest-version` ; then
       error "WARNING: unable to check for updates."
     elif [ "$LE_AUTO_VERSION" != "$REMOTE_VERSION" ]; then
       say "Upgrading certbot-auto $LE_AUTO_VERSION to $REMOTE_VERSION..."
diff --git a/letsencrypt-auto-source/tests/centos6_tests.sh b/letsencrypt-auto-source/tests/centos6_tests.sh
index e3ebbaec5..318325a36 100644
--- a/letsencrypt-auto-source/tests/centos6_tests.sh
+++ b/letsencrypt-auto-source/tests/centos6_tests.sh
@@ -47,6 +47,12 @@ if [ $RESULT -eq 0 ]; then
   exit 1
 fi
 
+# Skip self upgrade due to Python 3 not being available.
+if ! certbot/letsencrypt-auto-source/letsencrypt-auto 2>&1 | grep -q "WARNING: couldn't find Python"; then
+  echo "Python upgrade failure warning not printed!"
+  exit 1
+fi
+
 # bootstrap, this time installing python3
 certbot/letsencrypt-auto-source/letsencrypt-auto --no-self-upgrade -n > /dev/null 2> /dev/null