diff --git a/install.sh b/install.sh
index 81723904b6..645e49353e 100755
--- a/install.sh
+++ b/install.sh
@@ -58,6 +58,21 @@ nvm_profile_is_bash_or_zsh() {
 nvm_source() {
   local NVM_GITHUB_REPO
   NVM_GITHUB_REPO="${NVM_INSTALL_GITHUB_REPO:-nvm-sh/nvm}"
+  if [ "${NVM_GITHUB_REPO}" != 'nvm-sh/nvm' ]; then
+    { nvm_echo >&2 "$(cat)" ; } << EOF
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+@    WARNING: REMOTE REPO IDENTIFICATION HAS CHANGED!     @
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
+
+The default repository for this install is \`nvm-sh/nvm\`,
+but the environment variables \`\$NVM_INSTALL_GITHUB_REPO\` is
+currently set to \`${NVM_GITHUB_REPO}\`.
+
+If this is not intentional, interrupt this installation and
+verify your environment variables.
+EOF
+  fi
   local NVM_VERSION
   NVM_VERSION="${NVM_INSTALL_VERSION:-$(nvm_latest_version)}"
   local NVM_METHOD