diff --git a/src/mapreduce.jl b/src/mapreduce.jl
index a28e431..f5af91e 100644
--- a/src/mapreduce.jl
+++ b/src/mapreduce.jl
@@ -51,9 +51,13 @@ end
 
 # Implementation for special cases and if fallback breaks in future julia versions
 
-for fname in [:sum, :prod, :all, :any, :minimum, :maximum]
-    @eval Base.$fname(v::AbstractDiskArray) = Base.$fname(identity, v::AbstractDiskArray)
-    @eval function Base.$fname(f::Function, v::AbstractDiskArray)
+for (fname, _fname) in ((:sum, :_sum), (:prod, :_prod),
+                        (:all, :_all), (:any, :_any),
+                        (:minimum, :_minimum), (:maximum, :_maximum))
+    @eval Base.$fname(v::AbstractDiskArray; dims=:) = Base.$_fname(v, dims)
+    @eval Base.$fname(f::Function, v::AbstractDiskArray; dims=:) = Base.$_fname(f, v, dims)
+    @eval Base.$_fname(v::AbstractDiskArray, ::Colon) = Base.$_fname(identity, v, :)
+    @eval function Base.$_fname(f::Function, v::AbstractDiskArray, ::Colon)
         $fname(eachchunk(v)) do chunk
             $fname(f, v[chunk...])
         end
@@ -66,3 +70,24 @@ function Base.count(f, v::AbstractDiskArray)
         count(f, v[chunk...])
     end
 end
+
+for (_fname, init, acum) in ((:_sum, :zero, :+), (:_prod, :one, :*),
+                             (:_all, _->:true, :&), (:_any, _->:false, :|),
+                             (:_maximum, :typemin, :max), (:_minimum, :typemax, :min))
+    @eval Base.$_fname(a::AbstractDiskArray, dims)  = Base.$_fname(identity, a, dims)
+    @eval function Base.$_fname(f::Function, a::AbstractDiskArray{T,N}, dims) where {T,N}
+        _dims = typeof(dims)<:Tuple ? [dims...] : typeof(dims)<:Number ? [dims] : dims
+        out_dims = ntuple(Val(N)) do i
+            i in _dims ? 1 : size(a)[i]
+        end 
+        T1 = Base.promote_op(f, T)
+        out = fill($init(T1), out_dims...)
+        for c in eachchunk(a)
+            out_c = ntuple(Val(N)) do i
+                i in _dims ? (1:1) : c[i]
+            end 
+            out[out_c...] .= $acum.(out[out_c...], Base.$_fname(f, a[c...], dims))
+        end
+        return out
+    end
+end
diff --git a/test/runtests.jl b/test/runtests.jl
index 8ecefa2..e466ebb 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1059,3 +1059,28 @@ end
     end
     @test count(a) + count(!, a) == length(a)
 end
+
+@testset "dims kwarg" begin
+    a = ChunkedDiskArray(reshape(1:3*4*5, 3,4,5); chunksize=(2,3,4))
+    for fname in (:sum, :prod, :minimum, :maximum)
+        @test @eval $fname($a) == $fname(Array($a))
+        @test @eval $fname($a, dims=1) == $fname(Array($a), dims=1)
+        @test @eval $fname($a, dims=2) == $fname(Array($a), dims=2)
+        @test @eval $fname($a, dims=(1,2)) == $fname(Array($a), dims=(1,2))
+        @test @eval $fname(x->x/2, $a) ≈ $fname(x->x/2, Array($a))
+        @test @eval $fname(x->x/2, $a, dims=(1,2)) ≈ $fname(x->x/2, Array($a), dims=(1,2))
+        @eval out = @capture_out @trace $fname($a) DiskArrays
+        @test occursin("DiskGenerator", out) == false
+    end
+    b = ChunkedDiskArray(reshape(1:3*4*5 .> 10, 3,4,5); chunksize=(2,3,4))
+    for fname in (:all, :any)
+        @test @eval $fname($b) == $fname(Array($b))
+        @test @eval $fname($b, dims=1) == $fname(Array($b), dims=1)
+        @test @eval $fname($b, dims=2) == $fname(Array($b), dims=2)
+        @test @eval $fname($b, dims=(1,2)) == $fname(Array($b), dims=(1,2))
+        @test @eval $fname(!, $b) == $fname(!, Array($b))
+        @test @eval $fname(!, $b, dims=(1,2)) == $fname(!, Array($b), dims=(1,2))
+        @eval out = @capture_out @trace $fname($b) DiskArrays
+        @test occursin("DiskGenerator", out) == false
+    end
+end