diff --git a/tests/travis_trigger.sh b/tests/travis_trigger.sh
index 007f49f9..424f3950 100755
--- a/tests/travis_trigger.sh
+++ b/tests/travis_trigger.sh
@@ -1,30 +1,48 @@
 #!/bin/bash
 
+# Reference: https://docs.travis-ci.com/user/triggering-builds/
+
 set -e
 
 die() { echo "${*}"; exit 1; }
 usage() {
-    [ "${*}" ] && echo >&2 -e "${*}\n"
-    echo "Usage: $0 REPO BRANCH [VAR=VAL]...
+  [ "${*}" ] && echo >&2 -e "${*}\n"
+  echo "Usage: $0 REPO BRANCH [VAR=VAL]...
 
-    Examples:
+  Authorization:
 
-      Trigger build/test in self-hosted mode:
-        $0 REPO BRANCH DO_SELF_HOST=1
+    If you have the travis program installed then it will be called
+    to get an API token (you need to have done 'travis login --org'
+    in the past). Alternately you can explicity pass a token using
+    the TRAVIS_TOKEN environment variable. You can see your API
+    token at https://travis-ci.org/account/preferences.
 
-      Trigger build/test with stop on soft failures:
-        $0 REPO BRANCH DO_HARD=1
+  Travis .org vs .com:
 
-      Trigger build/test using regress mode on stepA:
-        $0 REPO BRANCH REGRESS=1 STEP=stepA
+    By default 'api.travis-ci.org' is used for API calls. This can
+    be overridden by setting TRAVIS_HOST="api.travis-ci.com"
 
-      Trigger build/test using regress mode on all steps:
-        $0 REPO BRANCH REGRESS=1
-    " | sed 's/^    //' >&2
+  Examples:
 
-    exit 2
+    Trigger build/test in self-hosted mode:
+      $0 REPO BRANCH DO_SELF_HOST=1
+
+    Trigger build/test with stop on soft failures:
+      $0 REPO BRANCH DO_HARD=1
+
+    Trigger build/test using regress mode on stepA:
+      $0 REPO BRANCH REGRESS=1 STEP=stepA
+
+    Trigger build/test using regress mode on all steps:
+      $0 REPO BRANCH REGRESS=1
+  " | sed 's/^  //' >&2
+
+  exit 2
 }
 
+TRAVIS_TOKEN="${TRAVIS_TOKEN:-}" # default to travis program
+TRAVIS_HOST="${TRAVIS_HOST:-api.travis-ci.org}"
+
 REPO="${1}"; shift || usage "REPO required"
 BRANCH="${1}"; shift || usage "BRANCH required"
 VARS="${*}"
@@ -45,12 +63,16 @@ body="{
   }
 }"
 
-token="$(travis token --org --no-interactive)"
+if [ -z "${TRAVIS_TOKEN}" ]; then
+    which travis >/dev/null \
+        || die "TRAVIS_TOKEN not set and travis command not found"
+    TRAVIS_TOKEN="$(travis token --org --no-interactive)"
+fi
 
 curl -X POST \
   -H "Content-Type: application/json" \
   -H "Accept: application/json" \
   -H "Travis-API-Version: 3" \
-  -H "Authorization: token ${token}" \
+  -H "Authorization: token ${TRAVIS_TOKEN}" \
   -d "$body" \
-  "https://api.travis-ci.org/repo/${repo}/requests"
+  "https://${TRAVIS_HOST}/repo/${repo}/requests"