diff --git a/lib/index.js b/lib/index.js
index 1e54765495ee6d793365846ecb2acb4825ba85f0..3a4db2a25252cf7d8217a67e5c1cdd21a70789d0 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -30,7 +30,7 @@ var Worker = function () {
 			return (/(debug|inspect)/.test(execArg)
 			);
 		});
-		if (debugVars.lenght > 0) {
+		if (debugVars.length > 0) {
 			if (!options.execArgv) {
 				//if no execArgs are given copy all arguments
 				debugVars = process.execArgv;
@@ -45,7 +45,7 @@ var Worker = function () {
 
 			if (portIndex > 0) {
 				//set new port, ignore "-brk", it doesn't work
-				debugVars[portIndex] = (/^--debug/.test(debugVars[portIndex]) ? "--debug=" : "--inspect=") + process.debugPort + 1;
+				debugVars[portIndex] = (/^--debug/.test(debugVars[portIndex]) ? "--debug=" : "--inspect=") + (process.debugPort + 1);
 			}
 			options.execArgv = options.execArgv.concat(debugVars);
 		}
diff --git a/src/index.js b/src/index.js
index 57783098695449df3522c412eb794678a8932731..fbd5f6d7dcc7c72e23b0f1e749652b85b856a858 100644
--- a/src/index.js
+++ b/src/index.js
@@ -16,7 +16,7 @@ class Worker {
 		var debugVars = process.execArgv.filter(execArg => {
 			return (/(debug|inspect)/).test(execArg);
 		});
-		if (debugVars.lenght > 0) {
+		if (debugVars.length > 0) {
 			if (!options.execArgv) { //if no execArgs are given copy all arguments
 				debugVars = process.execArgv;
 				options.execArgv = [];
@@ -27,7 +27,7 @@ class Worker {
 			});
 
 			if (portIndex > 0) { //set new port, ignore "-brk", it doesn't work
-				debugVars[portIndex] = ((/^--debug/).test(debugVars[portIndex]) ? "--debug=" : "--inspect=") + process.debugPort + 1;
+				debugVars[portIndex] = ((/^--debug/).test(debugVars[portIndex]) ? "--debug=" : "--inspect=") + (process.debugPort + 1);
 			}
 			options.execArgv = options.execArgv.concat(debugVars);