diff --git a/include/android/surface_control.h b/include/android/surface_control.h
index cce2e46..23461e2 100644
--- a/include/android/surface_control.h
+++ b/include/android/surface_control.h
@@ -346,7 +346,7 @@
  */
 void ASurfaceTransaction_setBuffer(ASurfaceTransaction* transaction,
                                    ASurfaceControl* surface_control, AHardwareBuffer* buffer,
-                                   int acquire_fence_fd = -1) __INTRODUCED_IN(29);
+                                   int acquire_fence_fd) __INTRODUCED_IN(29);
 
 /**
  * Updates the color for \a surface_control.  This will make the background color for the