diff --git a/src/AutGroup.jl b/src/AutGroup.jl
index e5d6540..10b3bc5 100644
--- a/src/AutGroup.jl
+++ b/src/AutGroup.jl
@@ -13,7 +13,7 @@ end
 
 typealias AutGroupElem GWord{AutSymbol}
 
-type AutGroup <: FPGroup
+type AutGroup <: AbstractFPGroup
    objectGroup::Group
    gens::Vector{AutSymbol}
 end
diff --git a/src/FreeGroup.jl b/src/FreeGroup.jl
index 1a73145..0642ab3 100644
--- a/src/FreeGroup.jl
+++ b/src/FreeGroup.jl
@@ -11,7 +11,7 @@ end
 
 typealias FreeGroupElem GWord{FreeSymbol}
 
-type FreeGroup <: FPGroup
+type FreeGroup <: AbstractFPGroup
    gens::Vector{FreeSymbol}
    #     order::Vector{T}
    #     fastmult_table::Array{Int,2}