diff --git a/lib/data/data-prefix.coffee b/lib/data/data-prefix.coffee
index 0ea125f7..f050fd11 100644
--- a/lib/data/data-prefix.coffee
+++ b/lib/data/data-prefix.coffee
@@ -5,11 +5,12 @@ prefix = null
 exports.get = ->
 	return prefix
 
-exports.set = (newPrefix) ->
+exports.set = (newPrefix, callback) ->
 	if not fsUtils.isValidPath(newPrefix)
-		throw new Error('Invalid path')
+		return callback?(new Error('Invalid path'))
 
 	prefix = newPrefix
+	return callback?(null, prefix)
 
 exports.clear = ->
 	prefix = null
diff --git a/lib/data/data-prefix.spec.coffee b/lib/data/data-prefix.spec.coffee
index 0abcb66a..591f8fc0 100644
--- a/lib/data/data-prefix.spec.coffee
+++ b/lib/data/data-prefix.spec.coffee
@@ -22,19 +22,22 @@ describe 'DataPrefix:', ->
 
 		describe '#set()', ->
 
-			it 'should be able to set a prefix', ->
+			it 'should be able to set a prefix', (done) ->
 				expect(dataPrefix.get()).to.not.exist
-				dataPrefix.set(PREFIXES.main)
-				expect(dataPrefix.get()).to.equal(PREFIXES.main)
+				dataPrefix.set PREFIXES.main, (error) ->
+					expect(error).to.not.exist
+					expect(dataPrefix.get()).to.equal(PREFIXES.main)
+					done()
 
-			it 'should throw an error if passing an invalid path', ->
-				setInvalidPrefix = _.partial(dataPrefix.set, PREFIXES.invalid)
-				expect(setInvalidPrefix).to.throw(Error)
+			it 'should throw an error if passing an invalid path', (done) ->
+				dataPrefix.set PREFIXES.invalid, (error) ->
+					expect(error).to.be.an.instanceof(Error)
+					done()
 
 	describe 'given a prefix', ->
 
-		beforeEach ->
-			dataPrefix.set(PREFIXES.main)
+		beforeEach (done) ->
+			dataPrefix.set(PREFIXES.main, done)
 
 		describe '#get()', ->
 
@@ -43,10 +46,12 @@ describe 'DataPrefix:', ->
 
 		describe '#set()', ->
 
-			it 'should be able to override the prefix', ->
+			it 'should be able to override the prefix', (done) ->
 				expect(dataPrefix.get()).to.equal(PREFIXES.main)
-				dataPrefix.set(PREFIXES.new)
-				expect(dataPrefix.get()).to.equal(PREFIXES.new)
+				dataPrefix.set PREFIXES.new, (error) ->
+					expect(error).to.not.exist
+					expect(dataPrefix.get()).to.equal(PREFIXES.new)
+					done()
 
 		describe '#clear()', ->
 
diff --git a/lib/data/data.spec.coffee b/lib/data/data.spec.coffee
index 7a2cf27e..b84c53eb 100644
--- a/lib/data/data.spec.coffee
+++ b/lib/data/data.spec.coffee
@@ -58,9 +58,9 @@ describe 'Data:', ->
 
 	describe 'given a prefix', ->
 
-		beforeEach ->
+		beforeEach (done) ->
 			mock.fs.init(FILESYSTEM)
-			data.prefix.set(config.dataPrefix)
+			data.prefix.set(config.dataPrefix, done)
 
 		afterEach ->
 			mock.fs.restore()
diff --git a/lib/fs-utils/fs-utils.spec.coffee b/lib/fs-utils/fs-utils.spec.coffee
index 0a5a6095..0cf26fd6 100644
--- a/lib/fs-utils/fs-utils.spec.coffee
+++ b/lib/fs-utils/fs-utils.spec.coffee
@@ -39,9 +39,9 @@ describe 'FsUtils:', ->
 
 	describe '#isDirectory()', ->
 
-		beforeEach ->
+		beforeEach (done) ->
 			mock.fs.init(FILESYSTEM)
-			data.prefix.set(config.dataPrefix)
+			data.prefix.set(config.dataPrefix, done)
 
 		afterEach ->
 			mock.fs.restore()