diff --git a/lib/controller/checks.py b/lib/controller/checks.py
index 4890559a0..89ebfba23 100644
--- a/lib/controller/checks.py
+++ b/lib/controller/checks.py
@@ -661,7 +661,7 @@ def checkFalsePositives(injection):
 
             # Just in case if DBMS hasn't properly recovered from previous delayed request
             if PAYLOAD.TECHNIQUE.BOOLEAN not in injection.data:
-                checkBooleanExpression("%d=%d", randInt1, randInt2)
+                checkBooleanExpression("%d=%d" % (randInt1, randInt2))
 
             if checkBooleanExpression("%d>(%d+%d)" % (min(randInt1, randInt2), randInt3, max(randInt1, randInt2))):
                 retVal = None