Index: src/os_win.c
==================================================================
--- src/os_win.c
+++ src/os_win.c
@@ -641,10 +641,17 @@
   lowerBits = GetFileSize(((winFile*)id)->h, &upperBits);
   *pSize = (((i64)upperBits)<<32) + lowerBits;
   return SQLITE_OK;
 }
 
+/*
+** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
+*/
+#ifndef LOCKFILE_FAIL_IMMEDIATELY
+# define LOCKFILE_FAIL_IMMEDIATELY 1
+#endif
+
 /*
 ** Acquire a reader lock.
 ** Different API routines are called depending on whether or not this
 ** is Win95 or WinNT.
 */