diff --git a/src/Item/Item.lua b/src/Item/Item.lua
index af7571a..8132913 100644
--- a/src/Item/Item.lua
+++ b/src/Item/Item.lua
@@ -366,8 +366,8 @@ function Item:Usable()
     if not self:EvaluateTraits() then
         return false
     end
-    if self:GetUsableFunction() then
-        return self:GetUsableFunction()(self)
+    if self:GetUsableFunction() and not self:GetUsableFunction()(self) then
+        return false
     end
 
     return self:IsEquippedAndUsable()
diff --git a/src/Spell/Spell.lua b/src/Spell/Spell.lua
index 510154b..e9c9d6e 100644
--- a/src/Spell/Spell.lua
+++ b/src/Spell/Spell.lua
@@ -421,9 +421,8 @@ function Spell:Castable()
     if not self:EvaluateTraits() then
         return false
     end
-    if self:GetCastableFunction() then
-        return self:GetCastableFunction()(self) and
-            self:IsKnownAndUsable(type(self.traits.cast.override) ~= nil and self.traits.cast.override or nil)
+    if self:GetCastableFunction() and not self:GetCastableFunction()(self) then
+        return false
     end
 
     return self:IsKnownAndUsable(type(self.traits.cast.override) ~= nil and self.traits.cast.override or nil)