diff --git a/src/base-traits.jl b/src/base-traits.jl
index 7c45d9a..e85f5a9 100644
--- a/src/base-traits.jl
+++ b/src/base-traits.jl
@@ -15,15 +15,15 @@ export IsLeafType, IsConcrete, IsBits, IsImmutable, IsContiguous, IsIndexLinear,
 
 "Trait of all isbits-types"
 @traitdef IsBits{X}
-Base.@pure _isbits(X) = isbitstype(X)
+_isbits(X) = isbitstype(X)
 @traitimpl IsBits{X} <- _isbits(X)
 
 "Trait of all immutable types"
 @traitdef IsImmutable{X}
 if VERSION >= v"1.7.0-DEV.1279"
-    Base.@pure _isimmutable(X) = !(Base.ismutabletype(X))
+    _isimmutable(X) = !(Base.ismutabletype(X))
 else
-    Base.@pure _isimmutable(X) = !X.mutable
+    _isimmutable(X) = !X.mutable
 end
 @traitimpl IsImmutable{X}  <- _isimmutable(X)