diff --git a/Project.toml b/Project.toml
index af3b030ab..680ead345 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "ChainRulesCore"
 uuid = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
-version = "0.9.41"
+version = "0.9.42"
 
 [deps]
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
diff --git a/src/accumulation.jl b/src/accumulation.jl
index 5c608550b..4bcc5c33f 100644
--- a/src/accumulation.jl
+++ b/src/accumulation.jl
@@ -24,6 +24,8 @@ function add!!(x, t::InplaceableThunk)
     end
 end
 
+add!!(x::AbstractArray, y::Thunk) = add!!(x, unthunk(y))
+
 function add!!(x::AbstractArray{<:Any, N}, y::AbstractArray{<:Any, N}) where N
     return if is_inplaceable_destination(x)
         x .+= y
diff --git a/test/accumulation.jl b/test/accumulation.jl
index 8b711d523..1ede27473 100644
--- a/test/accumulation.jl
+++ b/test/accumulation.jl
@@ -87,15 +87,13 @@
             end
         end
 
-        @testset "InplaceableThunk" begin
-            ithunk = InplaceableThunk(
-                @thunk(-1.0*ones(2, 2)),
-                x -> x .-= ones(2, 2)
-            )
-
+        @testset "AbstractThunk $(typeof(thunk))" for thunk in (
+            @thunk(-1.0*ones(2, 2)),
+            InplaceableThunk(@thunk(-1.0*ones(2, 2)), x -> x .-= ones(2, 2)),
+        )
             @testset "in place" begin
                 accumuland = [1.0 2.0; 3.0 4.0]
-                ret = add!!(accumuland, ithunk)
+                ret = add!!(accumuland, thunk)
                 @test ret == [0.0 1.0; 2.0 3.0]  # must return right answer
                 @test ret === accumuland  # must be same object
             end
@@ -103,7 +101,7 @@
             @testset "out of place" begin
                 accumuland = @SMatrix [1.0 2.0; 3.0 4.0]
 
-                ret = add!!(accumuland, ithunk)
+                ret = add!!(accumuland, thunk)
                 @test ret == [0.0 1.0; 2.0 3.0]  # must return right answer
                 @test ret !== accumuland  # must not be same object
                 @test accumuland == [1.0 2.0; 3.0 4.0]  # must not have mutated