diff --git a/external/cmapscompress/compress.js b/external/cmapscompress/compress.js
index d5e914729..81316fb47 100644
--- a/external/cmapscompress/compress.js
+++ b/external/cmapscompress/compress.js
@@ -204,7 +204,7 @@ function parseCMap(binaryData) {
         bufferSize = 0;
       while (s.length < lengthInChars) {
         while (bufferSize < 4 && stack.length > 0) {
-          buffer = (stack.pop() << bufferSize) | buffer;
+          buffer |= stack.pop() << bufferSize;
           bufferSize += 7;
         }
         s = toHexDigit(buffer & 15) + s;
@@ -375,7 +375,7 @@ function writeNumber(n) {
     let i = n.length;
     while (i > 0) {
       --i;
-      buffer = (fromHexDigit(n[i]) << bufferSize) | buffer;
+      buffer |= fromHexDigit(n[i]) << bufferSize;
       bufferSize += 4;
       if (bufferSize >= 7) {
         s = writeByte((buffer & 0x7f) | (s.length > 0 ? 0x80 : 0)) + s;
diff --git a/src/core/ascii_85_stream.js b/src/core/ascii_85_stream.js
index a006d40e2..9cabbc430 100644
--- a/src/core/ascii_85_stream.js
+++ b/src/core/ascii_85_stream.js
@@ -21,7 +21,7 @@ class Ascii85Stream extends DecodeStream {
     // Most streams increase in size when decoded, but Ascii85 streams
     // typically shrink by ~20%.
     if (maybeLength) {
-      maybeLength = 0.8 * maybeLength;
+      maybeLength *= 0.8;
     }
     super(maybeLength);
 
diff --git a/src/core/ascii_hex_stream.js b/src/core/ascii_hex_stream.js
index 0bc1bd15a..60fe007e6 100644
--- a/src/core/ascii_hex_stream.js
+++ b/src/core/ascii_hex_stream.js
@@ -20,7 +20,7 @@ class AsciiHexStream extends DecodeStream {
     // Most streams increase in size when decoded, but AsciiHex streams shrink
     // by 50%.
     if (maybeLength) {
-      maybeLength = 0.5 * maybeLength;
+      maybeLength *= 0.5;
     }
     super(maybeLength);
 
diff --git a/src/core/cmap.js b/src/core/cmap.js
index 1fe1dc599..63fd30c18 100644
--- a/src/core/cmap.js
+++ b/src/core/cmap.js
@@ -534,7 +534,7 @@ const BinaryCMapReader = (function BinaryCMapReaderClosure() {
         bufferSize = 0;
       while (i >= 0) {
         while (bufferSize < 8 && stack.length > 0) {
-          buffer = (stack[--sp] << bufferSize) | buffer;
+          buffer |= stack[--sp] << bufferSize;
           bufferSize += 7;
         }
         num[i] = buffer & 255;
diff --git a/src/core/jbig2.js b/src/core/jbig2.js
index 929240e4c..dbc430858 100644
--- a/src/core/jbig2.js
+++ b/src/core/jbig2.js
@@ -1088,7 +1088,7 @@ function decodeHalftoneRegion(
       bit = 0;
       patternIndex = 0;
       for (j = bitsPerValue - 1; j >= 0; j--) {
-        bit = grayScaleBitPlanes[j][mg][ng] ^ bit; // Gray decoding
+        bit ^= grayScaleBitPlanes[j][mg][ng]; // Gray decoding
         patternIndex |= bit << j;
       }
       patternBitmap = patterns[patternIndex];