diff --git a/lib/querystring.js b/lib/querystring.js
index 9b4ca27640aa71..3dc338b0d5c8b0 100644
--- a/lib/querystring.js
+++ b/lib/querystring.js
@@ -347,7 +347,7 @@ function parse(qs, sep, eq, options) {
         keyEncoded = valEncoded = customDecode;
         encodeCheck = 0;
         key = value = '';
-        posIdx = lastPos;
+        posIdx = i;
         lastPos = i + 1;
         sepIdx = eqIdx = 0;
       }
diff --git a/test/parallel/test-querystring.js b/test/parallel/test-querystring.js
index baa426094c77c6..b35cc68df9d7c7 100644
--- a/test/parallel/test-querystring.js
+++ b/test/parallel/test-querystring.js
@@ -59,6 +59,8 @@ const qsTestCases = [
   ['&&&&', '', {}],
   ['&=&', '=', { '': '' }],
   ['&=&=', '=&=', { '': [ '', '' ]}],
+  ['a&&b', 'a=&b=', { 'a': '', 'b': '' }],
+  ['a=a&&b=b', 'a=a&b=b', { 'a': 'a', 'b': 'b' }],
   [null, '', {}],
   [undefined, '', {}]
 ];