7a2cb106258aa7a18bcd53e45df96c4871a03d5e

 1diff --git a/tools/check_for_upgrade.sh b/tools/check_for_upgrade.sh
 2index 157b0cce2404dd2c9d7f134a48e3272a8577b022..8264762b6c5e3301f53a7e6245db710a2b85f976 100644
 3--- a/tools/check_for_upgrade.sh
 4+++ b/tools/check_for_upgrade.sh
 5@@ -54,14 +54,27 @@ function is_update_available() {
 6   [[ "$repo" = ohmyzsh/ohmyzsh ]] || return 0
 7   local api_url="https://api.github.com/repos/${repo}/commits/${branch}"
 8 
 9-  # Get local and remote HEADs and compare them. If we can't get either assume there are updates
10-  local local_head remote_head
11+  # Get local HEAD. If this fails assume there are updates
12+  local local_head
13   local_head=$(git -C "$ZSH" rev-parse $branch 2>/dev/null) || return 0
14 
15-  remote_head=$(curl -fsSL -H 'Accept: application/vnd.github.v3.sha' $api_url 2>/dev/null) \
16-  || remote_head=$(wget -O- --header='Accept: application/vnd.github.v3.sha' $api_url 2>/dev/null) \
17-  || remote_head=$(HTTP_ACCEPT='Accept: application/vnd.github.v3.sha' fetch -o - $api_url 2>/dev/null) \
18-  || return 0
19+  # Get remote HEAD. If we can't get it assume there are updates unless there is no connection:
20+  # - curl: 6 (could not resolve) or 7 (could not connect)
21+  # - wget: 4 (network unreachable)
22+  # - fetch: 1 (no route to host)
23+  local remote_head ret
24+  remote_head=$(
25+    curl -fsSL -H 'Accept: application/vnd.github.v3.sha' $api_url 2>/dev/null || {
26+      [[ $? -eq 6 || $? -eq 7 ]] && exit 1
27+    } || wget -O- --header='Accept: application/vnd.github.v3.sha' $api_url 2>/dev/null || {
28+      [[ $? -eq 4 ]] && exit 1
29+    } || HTTP_ACCEPT='Accept: application/vnd.github.v3.sha' fetch -o - $api_url 2>/dev/null || {
30+      [[ $? -eq 1 ]] && exit 1
31+    } || exit 0
32+  )
33+
34+  # If can't fetch remote HEAD, return exit code
35+  ret=$?; [[ -n "$remote_head" ]] || return $ret
36 
37   # Compare local and remote HEADs
38   [[ "$local_head" != "$remote_head" ]]