diff --git a/lib/parser.js b/lib/parser.js
index dc3eb54b..4145d7a3 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -19777,7 +19777,7 @@ module.exports = (function() {
     };
     if (!options.raw)
       r = p = rp = id;
-    eval('\n  // XXX: The functions below override the default code generated by PEGjs.\n  // CoffeeScriptRedux has a preprocessor that adds control characters to\n  // mark indents/outdents/etc for PEGjs. These characters cause the line,\n  // column, and offset values to differ from the original input source code,\n  // so this section exists to properly hide those control characters when\n  // reporting location information. See #117 & #335.\n\n  var csr$controlCharacterCount = 0;\n\n  function offset() {\n    return peg$reportedPos - csr$controlCharacterCount;\n  }\n\n  function peg$computePosDetails() {\n    function advanceCachedReportedPos() {\n      var ch;\n\n      for (; peg$cachedPos < peg$reportedPos; peg$cachedPos++) {\n        ch = input.charAt(peg$cachedPos);\n        if (ch === "\\n") {\n          if (!peg$cachedPosDetails.seenCR) { peg$cachedPosDetails.line++; }\n          peg$cachedPosDetails.column = 1;\n          peg$cachedPosDetails.seenCR = false;\n        } else if (ch === "\\r" || ch === "\\u2028" || ch === "\\u2029") {\n          peg$cachedPosDetails.line++;\n          peg$cachedPosDetails.column = 1;\n          peg$cachedPosDetails.seenCR = true;\n        } else if(!/[\\uEFEF\\uEFFE\\uEFFF]/.test(ch)) {\n          peg$cachedPosDetails.column++;\n          peg$cachedPosDetails.seenCR = false;\n        } else {\n          csr$controlCharacterCount++;\n        }\n      }\n    }\n\n    if (peg$cachedPos !== peg$reportedPos) {\n      if (peg$cachedPos > peg$reportedPos) {\n        csr$controlCharacterCount = 0;\n        peg$cachedPos = 0;\n        peg$cachedPosDetails = { line: 1, column: 1, seenCR: false };\n      }\n      advanceCachedReportedPos();\n    }\n\n    return peg$cachedPosDetails;\n  }\n  ');
+    eval('\n  // XXX: The functions below override the default code generated by PEGjs.\n  // CoffeeScriptRedux has a preprocessor that adds control characters to\n  // mark indents/outdents/etc for PEGjs. These characters cause the line,\n  // column, and offset values to differ from the original input source code,\n  // so this section exists to properly hide those control characters when\n  // reporting location information. See #117 & #335.\n\n  var csr$controlCharacterCount = 0;\n\n  function offset() {\n    return peg$reportedPos - csr$controlCharacterCount;\n  }\n\n  function peg$computePosDetails(pos) {\n    function advance(details, startPos, endPos) {\n      var p, ch;\n\n      for (p = startPos; p < endPos; p++) {\n        ch = input.charAt(p);\n        if (ch === "\\n") {\n          if (!details.seenCR) { details.line++; }\n          details.column = 1;\n          details.seenCR = false;\n        } else if (ch === "\\r" || ch === "\\u2028" || ch === "\\u2029") {\n          details.line++;\n          details.column = 1;\n          details.seenCR = true;\n        } else if(!/[\\uEFEF\\uEFFE\\uEFFF]/.test(ch)) {\n          details.column++;\n          details.seenCR = false;\n        } else {\n          csr$controlCharacterCount++;\n        }\n      }\n    }\n\n    if (peg$cachedPos !== pos) {\n      if (peg$cachedPos > pos) {\n        csr$controlCharacterCount = 0;\n        peg$cachedPos = 0;\n        peg$cachedPosDetails = { line: 1, column: 1, seenCR: false };\n      }\n      advance(peg$cachedPosDetails, peg$cachedPos, pos);\n      peg$cachedPos = pos;\n    }\n\n    return peg$cachedPosDetails;\n  }\n  ');
     function isOwn$(o, p) {
       return {}.hasOwnProperty.call(o, p);
     }
diff --git a/src/grammar.pegcoffee b/src/grammar.pegcoffee
index 862d9037..884d566a 100644
--- a/src/grammar.pegcoffee
+++ b/src/grammar.pegcoffee
@@ -272,36 +272,37 @@
     return peg$reportedPos - csr$controlCharacterCount;
   }
 
-  function peg$computePosDetails() {
-    function advanceCachedReportedPos() {
-      var ch;
+  function peg$computePosDetails(pos) {
+    function advance(details, startPos, endPos) {
+      var p, ch;
 
-      for (; peg$cachedPos < peg$reportedPos; peg$cachedPos++) {
-        ch = input.charAt(peg$cachedPos);
+      for (p = startPos; p < endPos; p++) {
+        ch = input.charAt(p);
         if (ch === "\n") {
-          if (!peg$cachedPosDetails.seenCR) { peg$cachedPosDetails.line++; }
-          peg$cachedPosDetails.column = 1;
-          peg$cachedPosDetails.seenCR = false;
+          if (!details.seenCR) { details.line++; }
+          details.column = 1;
+          details.seenCR = false;
         } else if (ch === "\r" || ch === "\u2028" || ch === "\u2029") {
-          peg$cachedPosDetails.line++;
-          peg$cachedPosDetails.column = 1;
-          peg$cachedPosDetails.seenCR = true;
+          details.line++;
+          details.column = 1;
+          details.seenCR = true;
         } else if(!/[\uEFEF\uEFFE\uEFFF]/.test(ch)) {
-          peg$cachedPosDetails.column++;
-          peg$cachedPosDetails.seenCR = false;
+          details.column++;
+          details.seenCR = false;
         } else {
           csr$controlCharacterCount++;
         }
       }
     }
 
-    if (peg$cachedPos !== peg$reportedPos) {
-      if (peg$cachedPos > peg$reportedPos) {
+    if (peg$cachedPos !== pos) {
+      if (peg$cachedPos > pos) {
         csr$controlCharacterCount = 0;
         peg$cachedPos = 0;
         peg$cachedPosDetails = { line: 1, column: 1, seenCR: false };
       }
-      advanceCachedReportedPos();
+      advance(peg$cachedPosDetails, peg$cachedPos, pos);
+      peg$cachedPos = pos;
     }
 
     return peg$cachedPosDetails;