diff --git a/Library/Homebrew/cmd/update.sh b/Library/Homebrew/cmd/update.sh
index 18c97239a6..22dc5c4b1c 100644
--- a/Library/Homebrew/cmd/update.sh
+++ b/Library/Homebrew/cmd/update.sh
@@ -633,7 +633,7 @@ EOS
 
       # HOMEBREW_UPDATE_FORCE and HOMEBREW_UPDATE_AUTO aren't modified here so ignore subshell warning.
       # shellcheck disable=SC2030
-      if [[ "${UPSTREAM_REPOSITORY_URL}" = "https://github.com/"* ]]
+      if [[ "${UPSTREAM_REPOSITORY_URL}" == "https://github.com/"* ]]
       then
         UPSTREAM_REPOSITORY="${UPSTREAM_REPOSITORY_URL#https://github.com/}"
         UPSTREAM_REPOSITORY="${UPSTREAM_REPOSITORY%.git}"