diff --git a/query_classifier/qc_sqlite/CMakeLists.txt b/query_classifier/qc_sqlite/CMakeLists.txt
index b3d028723..159e792f2 100644
--- a/query_classifier/qc_sqlite/CMakeLists.txt
+++ b/query_classifier/qc_sqlite/CMakeLists.txt
@@ -18,7 +18,7 @@ include_directories(${MARIADB_CONNECTOR_INCLUDE_DIR})
 
 add_library(qc_sqlite SHARED qc_sqlite.c qc_sqlite3.c builtin_functions.c)
 add_dependencies(qc_sqlite maxscale_sqlite)
-add_definitions(-DMAXSCALE -DSQLITE_ENABLE_UPDATE_DELETE_LIMIT -DSQLITE_OMIT_ATTACH -DSQLITE_OMIT_REINDEX -DSQLITE_OMIT_AUTOVACUUM -DSQLITE_OMIT_PRAGMA)
+add_definitions(-DMAXSCALE -DSQLITE_THREADSAFE=0 -DSQLITE_ENABLE_UPDATE_DELETE_LIMIT -DSQLITE_OMIT_ATTACH -DSQLITE_OMIT_REINDEX -DSQLITE_OMIT_AUTOVACUUM -DSQLITE_OMIT_PRAGMA)
 
 set_target_properties(qc_sqlite PROPERTIES VERSION "1.0.0")
 set_target_properties(qc_sqlite PROPERTIES LINK_FLAGS -Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/qc_sqlite.map)