diff --git a/REQUIRE b/REQUIRE
index a380330..36872b6 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,2 +1,2 @@
 julia 0.6
-Compat 0.27 # for Val constructor
+Compat 0.33 # for Compat.Test
diff --git a/src/TypeSortedCollections.jl b/src/TypeSortedCollections.jl
index 57b5d29..bf0c84f 100644
--- a/src/TypeSortedCollections.jl
+++ b/src/TypeSortedCollections.jl
@@ -181,7 +181,7 @@ end
 @generated function Base.mapreduce(f, op, v0, tsc::TypeSortedCollection{<:Any, N}) where {N}
     expr = Expr(:block)
     push!(expr.args, :(Base.@_inline_meta))
-    push!(expr.args, :(ret = Base.r_promote(op, v0)))
+    push!(expr.args, :(ret = v0))
     for i = 1 : N
         push!(expr.args, quote
             let vec = tsc.data[$i]
diff --git a/test/runtests.jl b/test/runtests.jl
index c503077..217f7ff 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,4 +1,4 @@
-using Base.Test
+using Compat.Test
 using TypeSortedCollections
 
 module M