diff --git a/src/file.cpp b/src/file.cpp
index 6d8c6d6f3..ec6fb8e78 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -1173,9 +1173,8 @@ namespace {
 			fstore_t f = {F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, s, 0};
 			if (fcntl(native_handle(), F_PREALLOCATE, &f) < 0)
 			{
-				// It appears Apple's new filesystem (APFS) does not
-				// support this control message and fails with EINVAL
-				// if so, just skip it
+				// MacOS returns EINVAL if the file already has the space
+				// pre-allocated. In which case we can just move on.
 				if (errno != EINVAL)
 				{
 					if (errno != ENOSPC)