diff --git a/lib/src/index.js b/lib/src/index.js
index 8dc98fa2..9768b444 100644
--- a/lib/src/index.js
+++ b/lib/src/index.js
@@ -21,6 +21,7 @@ function src(glob, opt) {
     read: true,
     buffer: true,
     sourcemaps: false,
+    passthrough: false
   }, opt);
   var pass, inputPass;
 
@@ -42,7 +43,7 @@ function src(glob, opt) {
     .pipe(resolveSymlinks())
     .pipe(through.obj(createFile));
 
-  if (options.since) {
+  if (options.since != null) {
     outputStream = outputStream
       .pipe(filterSince(options.since));
   }
@@ -52,7 +53,7 @@ function src(glob, opt) {
       .pipe(getContents(options));
   }
 
-  if (options.passthrough) {
+  if (options.passthrough === true) {
     inputPass = through.obj();
     outputStream = duplexify.obj(inputPass, merge(outputStream, inputPass));
   }