diff --git a/src/Constants.js b/src/Constants.js
index 43024237d..31e70c4f4 100644
--- a/src/Constants.js
+++ b/src/Constants.js
@@ -1,5 +1,5 @@
 CONSTANTS = {
-    Version:                "0.23.0",
+    Version:                "0.23.1",
     
 	//Max level for any skill, assuming no multipliers. Determined by max numerical value in javascript for experience
     //and the skill level formula in Player.js. Note that all this means it that when experience hits MAX_INT, then
@@ -94,6 +94,9 @@ CONSTANTS = {
     //Infiltration constants
     InfiltrationBribeBaseAmount: 100000, //Amount per clearance level
     
+    
+    HospitalCostPerHp: 25000,
+    
     MillisecondsPer20Hours: 72000000,
     GameCyclesPer20Hours: 72000000 / 200,
     
@@ -857,6 +860,8 @@ CONSTANTS = {
     "-You can now see what an Augmentation does and its price even while its locked<br><br>",
     
     LatestUpdate: 
+    "v0.23.1<br>" + 
+    "-scan() Netscript function now takes a single argument representing the server from which to scan. <br><br>" + 
     "v0.23.0<br>" + 
     "-You can now purchase multiple Augmentations in a run. When you purchase an Augmentation you will lose money equal to the price " + 
     "and then the cost of purchasing another Augmentation during this run will be increased by 75%. You do not gain the benefits " + 
diff --git a/src/NetscriptEvaluator.js b/src/NetscriptEvaluator.js
index a939af495..c72917736 100644
--- a/src/NetscriptEvaluator.js
+++ b/src/NetscriptEvaluator.js
@@ -204,20 +204,27 @@ function evaluate(exp, workerScript) {
                     });
                     
                 } else if (exp.func.value == "scan") {
-                    if (exp.args.length != 0) {
-                        return reject(makeRuntimeRejectMsg(workerScript, "scan() call has incorrect number of arguments. Takes 0 arguments"));
+                    if (exp.args.length != 1) {
+                        return reject(makeRuntimeRejectMsg(workerScript, "scan() call has incorrect number of arguments. Takes 1 argument"));
                     }
-                    var currServ = getServer(workerScript.serverIp);
-                    if (currServ == null) {
-                        return reject(makeRuntimeRejectMsg(workerScript, "Could not find server ip for this script. This is a bug please contact game developer"));
-                    }
-                    var res = [];
-                    for (var i = 0; i < currServ.serversOnNetwork.length; ++i) {
-                        var thisServ = getServer(currServ.serversOnNetwork[i]);
-                        if (thisServ == null) {continue;}
-                        res.push({type:"str", value: thisServ.hostname});
-                    }
-                    resolve(res);
+                    
+                    var ipPromise = evaluate(exp.args[0], workerScript);
+                    ipPromise.then(function(ip) {
+                        var server = getServer(ip);
+                        if (server == null) {
+                            workerScript.scriptRef.log("scan() failed. Invalid IP or hostname passed in: " + ip);
+                            return reject(makeRuntimeRejectMsg(workerScript, "Invalid IP or hostname passed into scan() command"));;
+                        }
+                        var res = [];
+                        for (var i = 0; i < server.serversOnNetwork.length; ++i) {
+                            var thisServ = getServer(server.serversOnNetwork[i]);
+                            if (thisServ == null) {continue;}
+                            res.push({type:"str", value: thisServ.hostname});
+                        }
+                        resolve(res);
+                    }, function(e) {
+                        reject(e);
+                    });
                 } else if (exp.func.value == "nuke") {
                     var p = netscriptRunProgram(exp, workerScript, Programs.NukeProgram);
                     p.then(function(res) {