diff --git a/sqlite3.go b/sqlite3.go
index d3a6407..bfb4d1f 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -7,7 +7,7 @@ package sqlite3
 
 /*
 #cgo CFLAGS: -std=gnu99
-#cgo CFLAGS: -DSQLITE_ENABLE_RTREE -DSQLITE_THREADSAFE
+#cgo CFLAGS: -DSQLITE_ENABLE_RTREE -DSQLITE_THREADSAFE=1
 #cgo CFLAGS: -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_FTS3_PARENTHESIS -DSQLITE_ENABLE_FTS4_UNICODE61
 #cgo CFLAGS: -DSQLITE_TRACE_SIZE_LIMIT=15
 #cgo CFLAGS: -DSQLITE_DISABLE_INTRINSIC