diff --git a/src/utils.coffee b/src/utils.coffee
index 526d33f..2e9b64e 100644
--- a/src/utils.coffee
+++ b/src/utils.coffee
@@ -44,8 +44,8 @@ utils.restoreDatabase = (connectionString, dirName, next) ->
     return next null, stdOut, stdErr
 
 utils.makeDumpCommand = (connectionString, dirName) ->
-  throw "No target directory given." unless dirName 
-  throw "Target directory must be a string" unless typeof dirName is "string"
+  throw new Error "No target directory given." unless dirName 
+  throw new Error "Target directory must be a string" unless typeof dirName is "string"
   connectionParameters = utils.parseConnectionString connectionString
   commandOptions = makeCommandOptions connectionParameters
   commandOptions.out = dirName
@@ -54,8 +54,8 @@ utils.makeDumpCommand = (connectionString, dirName) ->
   "mongodump#{argumentString}"
 
 utils.makeRestoreCommand = (connectionString, dirName) ->
-  throw "No source directory given." unless dirName 
-  throw "Source directory must be a string" unless typeof dirName is "string"
+  throw new Error "No source directory given." unless dirName 
+  throw new Error "Source directory must be a string" unless typeof dirName is "string"
   actualDirName = utils.findDumpDirName dirName
   utils.log "Using #{actualDirName}"
   connectionParameters = utils.parseConnectionString connectionString
@@ -122,4 +122,4 @@ makeCommandArguments = (options, object) ->
 makeArgumentString = (args) ->
   str = ""
   str += " '#{arg}'" for arg in args
-  str
\ No newline at end of file
+  str