diff --git a/src/fmdb/FMDatabase.m b/src/fmdb/FMDatabase.m
index 614d84c..be09dc2 100644
--- a/src/fmdb/FMDatabase.m
+++ b/src/fmdb/FMDatabase.m
@@ -1303,6 +1303,7 @@ static NSString *FMDBEscapeSavePointName(NSString *savepointName) {
 
 #pragma mark Callback function
 
+void FMDBBlockSQLiteCallBackFunction(sqlite3_context *context, int argc, sqlite3_value **argv); // -Wmissing-prototypes
 void FMDBBlockSQLiteCallBackFunction(sqlite3_context *context, int argc, sqlite3_value **argv) {
 #if ! __has_feature(objc_arc)
     void (^block)(sqlite3_context *context, int argc, sqlite3_value **argv) = (id)sqlite3_user_data(context);