diff --git a/.travis.yml b/.travis.yml
index 392b52e..e8a4731 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,4 +7,8 @@ services:
 
 before_install:
   - docker build -t eficode/wait-for .
+
+script:
+  - npm install
+  - ./run_tests.sh
   - docker run eficode/wait-for
diff --git a/Dockerfile b/Dockerfile
index 412d8e1..f636844 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,4 +8,5 @@ WORKDIR /app
 COPY . /app
 RUN npm install
 
-CMD ./node_modules/.bin/bats wait-for.bats
+# On launch, run the test suite via npm
+CMD npm test
diff --git a/package.json b/package.json
index 977ac4a..7aea0e7 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "wait-for",
   "version": "0.1.0",
   "scripts": {
-    "test": "./node_modules/.bin/bats wait-for.bats"
+    "test": "./run_tests.sh"
   },
   "dependencies": {
     "bats": "^0.4.2"
diff --git a/run_tests.sh b/run_tests.sh
new file mode 100755
index 0000000..13bf63a
--- /dev/null
+++ b/run_tests.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+# Although it would be possible to just call this directly from the Dockerfile,
+# centralizing tests in this file allows both the docker container and the
+# CI machine to run the same set of tests for an additional datapoint --
+# which gives a better chance of turning up POSIX noncompliance
+
+./node_modules/.bin/bats wait-for.bats
\ No newline at end of file
diff --git a/wait-for b/wait-for
index d6b04d8..a553daf 100755
--- a/wait-for
+++ b/wait-for
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 OLD_TIMEOUT=$TIMEOUT
 OLD_QUIET=$QUIET
@@ -34,7 +34,7 @@ USAGE
 
 test_connection() {
   # force a 1-second timeout on darwin (https://stackoverflow.com/a/20460402/2063546)
-  if [ -z "${$OSTYPE##*darwin*}" ] ; then
+  if [ -z "${OSTYPE##*darwin*}" ] ; then
     nc -w 1 -G 1 "$1" "$2" > /dev/null 2>&1
   else
     nc -w 1 "$1" "$2" > /dev/null 2>&1