diff --git a/okhttp/src/test/java/io/grpc/okhttp/OkHttpWritableBufferAllocatorTest.java b/okhttp/src/test/java/io/grpc/okhttp/OkHttpWritableBufferAllocatorTest.java
index d423ba313d5..c444e0ee11d 100644
--- a/okhttp/src/test/java/io/grpc/okhttp/OkHttpWritableBufferAllocatorTest.java
+++ b/okhttp/src/test/java/io/grpc/okhttp/OkHttpWritableBufferAllocatorTest.java
@@ -55,8 +55,8 @@ public void testInitialCapacityHasMaximum() {
 
   @Test
   public void testIsExactBelowMaxCapacity() {
-    WritableBuffer buffer = allocator().allocate(4097);
+    WritableBuffer buffer = allocator().allocate(Segment.SIZE + 1);
     assertEquals(0, buffer.readableBytes());
-    assertEquals(Segment.SIZE, buffer.writableBytes());
+    assertEquals(Segment.SIZE * 2, buffer.writableBytes());
   }
 }