2 files changed, 3 insertions, 0 deletions
diff --git a/src/os_unix.c b/src/os_unix.c
index 6eed67407..30d79f0c5 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3152,6 +3152,8 @@ static int unixRead(
   unixFile *pFile = (unixFile *)id;
   int got;
   assert( id );
+  assert( offset>=0 );
+  assert( amt>0 );
 
   /* If this is a database file (not a journal, master-journal or temp
   ** file), the bytes in the locking range should never be read or written. */
diff --git a/src/os_win.c b/src/os_win.c
index e30824815..66f070387 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -2157,6 +2157,7 @@ static int winRead(
 
   assert( id!=0 );
   assert( amt>0 );
+  assert( offset>=0 );
   SimulateIOError(return SQLITE_IOERR_READ);
   OSTRACE(("READ file=%p, buffer=%p, amount=%d, offset=%lld, lock=%d\n",
            pFile->h, pBuf, amt, offset, pFile->locktype));