diff --git a/index.js b/index.js
index 1d09e26..41e1cd3 100644
--- a/index.js
+++ b/index.js
@@ -38,6 +38,7 @@ function rangeParser (size, str, options) {
   // split the range string
   var arr = str.slice(index + 1).split(',')
   var ranges = []
+  var valid = false
 
   // add ranges type
   ranges.type = str.slice(0, index)
@@ -46,7 +47,7 @@ function rangeParser (size, str, options) {
   for (var i = 0; i < arr.length; i++) {
     var indexOf = arr[i].indexOf('-')
     if (indexOf === -1) {
-      return -2
+      continue
     }
 
     var startStr = arr[i].slice(0, indexOf).trim()
@@ -67,12 +68,14 @@ function rangeParser (size, str, options) {
       end = size - 1
     }
 
+    // invalid format range
     if (isNaN(start) || isNaN(end)) {
-      return -2
+      continue
     }
 
-    // invalid or unsatisifiable
+    // skip unsatisfiable ranges
     if (start > end || start < 0) {
+      valid = true
       continue
     }
 
@@ -84,8 +87,7 @@ function rangeParser (size, str, options) {
   }
 
   if (ranges.length < 1) {
-    // unsatisifiable
-    return -1
+    return valid ? -1 : -2
   }
 
   return options && options.combine
diff --git a/test/range-parser.js b/test/range-parser.js
index f882a93..9f2c483 100644
--- a/test/range-parser.js
+++ b/test/range-parser.js
@@ -1,4 +1,3 @@
-
 var assert = require('assert')
 var deepEqual = require('deep-equal')
 var parse = require('..')
@@ -9,6 +8,15 @@ describe('parseRange(len, str)', function () {
       /TypeError: argument str must be a string/)
   })
 
+  it('should return -2 for completely empty header', function () {
+    assert.strictEqual(parse(200, ''), -2)
+  })
+
+  it('should return -2 for range missing dash', function () {
+    assert.strictEqual(parse(200, 'bytes=100200'), -2)
+    assert.strictEqual(parse(200, 'bytes=,100200'), -2)
+  })
+
   it('should return -2 for invalid str', function () {
     assert.strictEqual(parse(200, 'malformed'), -2)
   })
@@ -28,6 +36,12 @@ describe('parseRange(len, str)', function () {
     assert.strictEqual(parse(200, 'bytes= - '), -2)
   })
 
+  it('should return -2 for empty range value', function () {
+    assert.strictEqual(parse(200, 'bytes='), -2)
+    assert.strictEqual(parse(200, 'bytes=,'), -2)
+    assert.strictEqual(parse(200, 'bytes= , , '), -2)
+  })
+
   it('should return -2 with multiple dashes in range', function () {
     assert.strictEqual(parse(200, 'bytes=100-200-300'), -2)
   })
@@ -41,6 +55,12 @@ describe('parseRange(len, str)', function () {
     assert.strictEqual(parse(200, 'bytes=100-15b0'), -2)
   })
 
+  it('should return -2 when all multiple ranges have invalid format', function () {
+    assert.strictEqual(parse(200, 'bytes=y-v,x-'), -2)
+    assert.strictEqual(parse(200, 'bytes=abc-def,ghi-jkl'), -2)
+    assert.strictEqual(parse(200, 'bytes=x-,y-,z-'), -2)
+  })
+
   it('should return -1 for unsatisfiable range', function () {
     assert.strictEqual(parse(200, 'bytes=500-600'), -1)
   })
@@ -55,6 +75,12 @@ describe('parseRange(len, str)', function () {
     assert.strictEqual(parse(200, 'bytes=500-999,1000-1499'), -1)
   })
 
+  it('should return -1 for mixed invalid and unsatisfiable ranges', function () {
+    assert.strictEqual(parse(200, 'bytes=abc-def,500-999'), -1)
+    assert.strictEqual(parse(200, 'bytes=500-999,xyz-uvw'), -1)
+    assert.strictEqual(parse(200, 'bytes=abc-def,500-999,xyz-uvw'), -1)
+  })
+
   it('should parse str', function () {
     var range = parse(1000, 'bytes=0-499')
     assert.strictEqual(range.type, 'bytes')
@@ -111,6 +137,28 @@ describe('parseRange(len, str)', function () {
     deepEqual(range[0], { start: 999, end: 999 })
   })
 
+  it('should ignore invalid format range when valid range exists', function () {
+    var range = parse(1000, 'bytes=100-200,x-')
+    assert.strictEqual(range.type, 'bytes')
+    assert.strictEqual(range.length, 1)
+    deepEqual(range[0], { start: 100, end: 200 })
+  })
+
+  it('should ignore invalid format ranges when some are valid', function () {
+    var range = parse(1000, 'bytes=x-,0-100,y-')
+    assert.strictEqual(range.type, 'bytes')
+    assert.strictEqual(range.length, 1)
+    deepEqual(range[0], { start: 0, end: 100 })
+  })
+
+  it('should ignore invalid format ranges at different positions', function () {
+    var range = parse(1000, 'bytes=0-50,abc-def,100-150')
+    assert.strictEqual(range.type, 'bytes')
+    assert.strictEqual(range.length, 2)
+    deepEqual(range[0], { start: 0, end: 50 })
+    deepEqual(range[1], { start: 100, end: 150 })
+  })
+
   it('should parse str with multiple ranges', function () {
     var range = parse(1000, 'bytes=40-80,81-90,-1')
     assert.strictEqual(range.type, 'bytes')
@@ -161,4 +209,11 @@ describe('parseRange(len, str)', function () {
       deepEqual(range[2], { start: 0, end: 1 })
     })
   })
+
+  it('should ignore whitespace-only invalid ranges when valid present', function () {
+    var range = parse(1000, 'bytes= , 0-10')
+    assert.strictEqual(range.type, 'bytes')
+    assert.strictEqual(range.length, 1)
+    deepEqual(range[0], { start: 0, end: 10 })
+  })
 })