diff --git a/apps/openmw/mwmechanics/npcstats.cpp b/apps/openmw/mwmechanics/npcstats.cpp
index ca58f4825..facfa0eb0 100644
--- a/apps/openmw/mwmechanics/npcstats.cpp
+++ b/apps/openmw/mwmechanics/npcstats.cpp
@@ -121,7 +121,7 @@ float MWMechanics::NpcStats::getSkillGain (int skillIndex, const ESM::Class& cla
     {
         skillFactor = skill->mData.mUseValue[usageType];
 
-        if (skillFactor<=0)
+        if (skillFactor<0)
             throw std::runtime_error ("invalid skill gain factor");
     }