diff --git a/cmd/cindex/cindex.go b/cmd/cindex/cindex.go
index 5960b48a6e..85aaaeb1ff 100644
--- a/cmd/cindex/cindex.go
+++ b/cmd/cindex/cindex.go
@@ -24,7 +24,8 @@ const (
 	DEFAULT_MAX_FILE_LENGTH             = 1 << 30
 	DEFAULT_MAX_LINE_LENGTH             = 2000
 	DEFAULT_MAX_TEXT_TRIGRAMS           = 30000
-	DEFAULT_MAX_INVALID_UTF8_PERCENTAGE = 0.1
+	DEFAULT_MAX_INVALID_UTF8_RATIO      = 0.1
+	DEFAULT_MAX_NULL_RATIO              = 0.1
 )
 
 var usageMessage = `usage: cindex [options] [path...]
@@ -49,6 +50,8 @@ Options:
                skip indexing a file if it has more than this number of trigrams (Default: %v)
   -maxinvalidutf8ratio RATIO
                skip indexing a file if it has more than this ratio of invalid UTF-8 sequences (Default: %v)
+  -max-null-ratio RATIO
+               skip indexing a file if it has more than this ratio of null bytes (Default: %v)
   -exclude FILE
                path to file containing a list of file patterns to exclude from indexing
   -filelist FILE
@@ -83,7 +86,7 @@ With no path arguments, cindex -reset removes the index.
 `
 
 func usage() {
-	fmt.Fprintf(os.Stderr, usageMessage, DEFAULT_MAX_FILE_LENGTH, DEFAULT_MAX_LINE_LENGTH, DEFAULT_MAX_TEXT_TRIGRAMS, DEFAULT_MAX_INVALID_UTF8_PERCENTAGE)
+	fmt.Fprintf(os.Stderr, usageMessage, DEFAULT_MAX_FILE_LENGTH, DEFAULT_MAX_LINE_LENGTH, DEFAULT_MAX_TEXT_TRIGRAMS, DEFAULT_MAX_INVALID_UTF8_RATIO, DEFAULT_MAX_NULL_RATIO)
 	os.Exit(2)
 }
 
@@ -107,7 +110,8 @@ var (
 	maxFileLen          = flag.Int64("maxfilelen", DEFAULT_MAX_FILE_LENGTH, "skip indexing a file if longer than this size in bytes")
 	maxLineLen          = flag.Int("maxlinelen", DEFAULT_MAX_LINE_LENGTH, "skip indexing a file if it has a line longer than this size in bytes")
 	maxTextTrigrams     = flag.Int("maxtrigrams", DEFAULT_MAX_TEXT_TRIGRAMS, "skip indexing a file if it has more than this number of trigrams")
-	maxInvalidUTF8Ratio = flag.Float64("maxinvalidutf8ratio", DEFAULT_MAX_INVALID_UTF8_PERCENTAGE, "skip indexing a file if it has more than this ratio of invalid UTF-8 sequences")
+	maxInvalidUTF8Ratio = flag.Float64("maxinvalidutf8ratio", DEFAULT_MAX_INVALID_UTF8_RATIO, "skip indexing a file if it has more than this ratio of invalid UTF-8 sequences")
+	maxNullRatio        = flag.Float64("max-null-ratio", DEFAULT_MAX_NULL_RATIO, "skip indexing a file if it has more than this ratio of null bytes")
 
 	excludePatterns = []string{
 		".csearchindex",
@@ -350,6 +354,7 @@ func main() {
 	ix.MaxLineLen = *maxLineLen
 	ix.MaxTextTrigrams = *maxTextTrigrams
 	ix.MaxInvalidUTF8Ratio = *maxInvalidUTF8Ratio
+	ix.MaxNullRatio = *maxNullRatio
 	ix.AddPaths(args)
 
 	walkChan := make(chan string)
diff --git a/index/write.go b/index/write.go
index de5e514091..ce2df7abb4 100644
--- a/index/write.go
+++ b/index/write.go
@@ -61,6 +61,7 @@ type IndexWriter struct {
 	MaxTextTrigrams int
 
 	MaxInvalidUTF8Ratio float64
+	MaxNullRatio float64
 }
 
 const npost = 64 << 20 / 8 // 64 MB worth of post entries
@@ -141,9 +142,11 @@ func (ix *IndexWriter) Add(name string, f io.Reader, size int64) {
 		n           = int64(0)
 		linelen     = 0
 		inv_cnt     = int64(0)
+		null_cnt     = int64(0)
 		b1          = byte(0)
 		b2          = byte(0)
 		max_invalid = int64(float64(size) * ix.MaxInvalidUTF8Ratio)
+		max_null = int64(float64(size) * ix.MaxNullRatio)
 	)
 	for {
 		tv = (tv << 8) & (1<<24 - 1)
@@ -172,7 +175,7 @@ func (ix *IndexWriter) Add(name string, f io.Reader, size int64) {
 			if !validUTF8(b1, b2) {
 				if inv_cnt++; inv_cnt > max_invalid {
 					if ix.LogSkip {
-						log.Printf("%s: skipped. High invalid UTF-8 ratio. total: %d invalid: %d ratio: %f\n", name, size, inv_cnt, float64(inv_cnt)/float64(size))
+						log.Printf("%s: skipped. High invalid UTF-8 ratio. total: %d, invalid: %d, ratio: %f\n", name, size, inv_cnt, float64(inv_cnt)/float64(size))
 					}
 					return
 				}
@@ -180,11 +183,13 @@ func (ix *IndexWriter) Add(name string, f io.Reader, size int64) {
 				ix.trigram.Add(tv)
 			}
 		}
-		if (b1 == 0x00 || b2 == 0x00) && n >= 3 {
-			if ix.LogSkip {
-				log.Printf("%s: skipped. Binary file. Bytes %02X%02X at offset %d\n", name, (tv>>8)&0xFF, tv&0xFF, n)
+		if c == 0x00 {
+			if null_cnt++; null_cnt > max_null {
+				if ix.LogSkip {
+					log.Printf("%s: skipped. High null byte ratio. total: %d, null: %d, ratio: %f\n", name, size, null_cnt, float64(null_cnt)/float64(size))
+				}
+				return
 			}
-			return
 		}
 		if linelen++; linelen > ix.MaxLineLen {
 			if ix.LogSkip {