diff --git a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
index 532ff3ad99b8..57be310f0027 100644
--- a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
@@ -1348,15 +1348,16 @@ public final void writeUInt32NoTag(int value) throws IOException {
     public final void writeFixed32NoTag(int value) throws IOException {
       int position = this.position; // Perf: hoist field to register to avoid load/stores.
       try {
-        buffer[position++] = (byte) (value & 0xFF);
-        buffer[position++] = (byte) ((value >> 8) & 0xFF);
-        buffer[position++] = (byte) ((value >> 16) & 0xFF);
-        buffer[position++] = (byte) ((value >> 24) & 0xFF);
+        buffer[position] = (byte) (value & 0xFF);
+        buffer[position + 1] = (byte) ((value >> 8) & 0xFF);
+        buffer[position + 2] = (byte) ((value >> 16) & 0xFF);
+        buffer[position + 3] = (byte) ((value >> 24) & 0xFF);
       } catch (IndexOutOfBoundsException e) {
         throw new OutOfSpaceException(
-            String.format("Pos: %d, limit: %d, len: %d", position, limit, 1), e);
+            String.format("Pos: %d, limit: %d, len: %d", position, limit, FIXED32_SIZE), e);
       }
-      this.position = position; // Only update position if we stayed within the array bounds.
+      // Only update position if we stayed within the array bounds.
+      this.position = position + FIXED32_SIZE;
     }
 
     @Override
@@ -1393,19 +1394,20 @@ public final void writeUInt64NoTag(long value) throws IOException {
     public final void writeFixed64NoTag(long value) throws IOException {
       int position = this.position; // Perf: hoist field to register to avoid load/stores.
       try {
-        buffer[position++] = (byte) ((int) (value) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 8) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 16) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 24) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 32) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 40) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 48) & 0xFF);
-        buffer[position++] = (byte) ((int) (value >> 56) & 0xFF);
+        buffer[position] = (byte) ((int) (value) & 0xFF);
+        buffer[position + 1] = (byte) ((int) (value >> 8) & 0xFF);
+        buffer[position + 2] = (byte) ((int) (value >> 16) & 0xFF);
+        buffer[position + 3] = (byte) ((int) (value >> 24) & 0xFF);
+        buffer[position + 4] = (byte) ((int) (value >> 32) & 0xFF);
+        buffer[position + 5] = (byte) ((int) (value >> 40) & 0xFF);
+        buffer[position + 6] = (byte) ((int) (value >> 48) & 0xFF);
+        buffer[position + 7] = (byte) ((int) (value >> 56) & 0xFF);
       } catch (IndexOutOfBoundsException e) {
         throw new OutOfSpaceException(
-            String.format("Pos: %d, limit: %d, len: %d", position, limit, 1), e);
+            String.format("Pos: %d, limit: %d, len: %d", position, limit, FIXED64_SIZE), e);
       }
-      this.position = position; // Only update position if we stayed within the array bounds.
+      // Only update position if we stayed within the array bounds.
+      this.position = position + FIXED64_SIZE;
     }
 
     @Override