diff --git a/src/shared/util.js b/src/shared/util.js
index de33f2be9..c19a588e0 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -2166,7 +2166,7 @@ if (typeof PDFJSDev === 'undefined' || !PDFJSDev.test('MOZCENTRAL')) {
               err('\\ not allowed in relative path.');
             }
             var tmp;
-            if (tmp = relativePathDotMapping[buffer.toLowerCase()]) {
+            if ((tmp = relativePathDotMapping[buffer.toLowerCase()])) {
               buffer = tmp;
             }
             if ('..' === buffer) {
diff --git a/web/compatibility.js b/web/compatibility.js
index f040e2a27..4300686e5 100644
--- a/web/compatibility.js
+++ b/web/compatibility.js
@@ -270,7 +270,7 @@ if (typeof PDFJS === 'undefined') {
       // initialize result and counters
       var bc = 0, bs, buffer, idx = 0, output = '';
       // get next character
-      buffer = input.charAt(idx++);
+      (buffer = input.charAt(idx++));
       // character found in table?
       // initialize bit storage and add its ascii value
       ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,