diff --git a/src/util/MongoBinary.js b/src/util/MongoBinary.js
index 390804bb7..78f9e1f13 100644
--- a/src/util/MongoBinary.js
+++ b/src/util/MongoBinary.js
@@ -131,7 +131,7 @@ export default class MongoBinary {
 
     if (opts.debug) {
       if (typeof opts.debug === 'function' && opts.debug.apply && opts.debug.call) {
-        debug = opts.debug;
+        this.debug = opts.debug;
       } else {
         this.debug = console.log.bind(null);
       }
@@ -149,7 +149,7 @@ export default class MongoBinary {
     if (systemBinary) {
       binaryPath = await this.getSystemPath(systemBinary);
       if (binaryPath) {
-        const binaryVersion = execSync('mongod --version')
+        const binaryVersion = execSync(`${binaryPath} --version`)
           .toString()
           .split('\n')[0]
           .split(' ')[2];
diff --git a/yarn.lock b/yarn.lock
index f490411a3..9eb5e2a5c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2200,6 +2200,11 @@ decompress@^4.2.0:
     pify "^2.3.0"
     strip-dirs "^2.0.0"
 
+dedent@^0.7.0:
+  version "0.7.0"
+  resolved "https://registry.yarnpkg.com/dedent/-/dedent-0.7.0.tgz#2495ddbaf6eb874abb0e1be9df22d2e5a544326c"
+  integrity sha1-JJXduvbrh0q7Dhvp3yLS5aVEMmw=
+
 deep-extend@^0.6.0:
   version "0.6.0"
   resolved "https://registry.yarnpkg.com/deep-extend/-/deep-extend-0.6.0.tgz#c4fa7c95404a17a9c3e8ca7e1537312b736330ac"