diff --git a/direct-sqlite.cabal b/direct-sqlite.cabal
index b7b9f7d..1596b1d 100644
--- a/direct-sqlite.cabal
+++ b/direct-sqlite.cabal
@@ -51,9 +51,9 @@ flag json1
   default:     True
   description: Enable json1 extension.
 
-flag mathfunctions
+flag nomutex
   default:     False
-  description: Enable built-in mathematical functions
+  description: In this mode, SQLite can be safely used by multiple threads provided that no single database connection is used simultaneously in two or more threads.
 
 flag dbstat
   default:     True
@@ -96,8 +96,8 @@ library
     if flag(json1)
       cc-options: -DSQLITE_ENABLE_JSON1
 
-    if flag(mathfunctions)
-      cc-options: -DSQLITE_ENABLE_MATH_FUNCTIONS
+    if flag(nomutex)
+      cc-options: -DSQLITE_THREADSAFE=2
 
     if flag(dbstat)
       cc-options: -DSQLITE_ENABLE_DBSTAT_VTAB