diff --git a/plugins/dbms/mysql/fingerprint.py b/plugins/dbms/mysql/fingerprint.py
index 1acc5fb3b..ef89fcc29 100644
--- a/plugins/dbms/mysql/fingerprint.py
+++ b/plugins/dbms/mysql/fingerprint.py
@@ -174,7 +174,7 @@ class Fingerprint(GenericFingerprint):
             infoMsg = "confirming %s" % DBMS.MYSQL
             logger.info(infoMsg)
 
-            result = inject.checkBooleanExpression("USER()=USER()")
+            result = inject.checkBooleanExpression("USER() LIKE USER()")
 
             if not result:
                 warnMsg = "the back-end DBMS is not %s" % DBMS.MYSQL
diff --git a/xml/queries.xml b/xml/queries.xml
index 25630719e..b6f3b2820 100644
--- a/xml/queries.xml
+++ b/xml/queries.xml
@@ -397,8 +397,7 @@
    <dbms value="Firebird">
         <cast query="CAST(%s AS VARCHAR(10000))"/>
         <length query="CHAR_LENGTH(%s)"/>
-        <!-- TODO: add proper value -->
-        <delimiter query=""/>
+        <delimiter query="||"/>
         <limit query="ROWS %d TO %d"/>
         <limitregexp query="\s+ROWS\s+([\d]+)(\s+\TO\s+([\d]+))?"/>
         <limitgroupstart query="1"/>