diff --git a/Project.toml b/Project.toml
index 26589c7..a24037d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "OMEinsum"
 uuid = "ebe7aa44-baf0-506c-a96f-8464559b3922"
 authors = ["Andreas Peter <andreas.peter.ch@gmail.com>"]
-version = "0.8.0"
+version = "0.8.1"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
diff --git a/src/unaryrules.jl b/src/unaryrules.jl
index 95f2b2e..fbcf6fa 100644
--- a/src/unaryrules.jl
+++ b/src/unaryrules.jl
@@ -72,8 +72,20 @@ function compactify!(y, x, ix, iy, sx, sy)
 end
 
 function _compactify!(y, x, indexer, sx, sy)
-    @inbounds for ci in CartesianIndices(y)
-        y[ci] = sy * y[ci] + sx * x[subindex(indexer, ci.I)]
+    if iszero(sy)
+        if isone(sx)
+            @inbounds for ci in CartesianIndices(y)
+                y[ci] = x[subindex(indexer, ci.I)]
+            end
+        else
+            @inbounds for ci in CartesianIndices(y)
+                y[ci] = sx * x[subindex(indexer, ci.I)]
+            end
+        end
+    else
+        @inbounds for ci in CartesianIndices(y)
+            y[ci] = sy * y[ci] + sx * x[subindex(indexer, ci.I)]
+        end
     end
     return y
 end
diff --git a/test/unaryrules.jl b/test/unaryrules.jl
index a1d8bc3..130936b 100644
--- a/test/unaryrules.jl
+++ b/test/unaryrules.jl
@@ -18,7 +18,10 @@ end
     size_dict = Dict(1=>3,2=>3,3=>3)
     x = randn(3,3,3,3,3)
     y = randn(3,3,3)
-    @test unary_einsum!(Diag(), ix, iy, x, y, true, false) ≈ OMEinsum.loop_einsum(EinCode((ix,),iy), (x,), size_dict)
+    @test unary_einsum!(Diag(), ix, iy, x, copy(y), true, false) ≈ OMEinsum.loop_einsum(EinCode((ix,),iy), (x,), size_dict)
+    @test unary_einsum!(Diag(), ix, iy, x, copy(y), 2.0, 0.0) ≈ 2* OMEinsum.loop_einsum(EinCode((ix,),iy), (x,), size_dict)
+    @test unary_einsum!(Diag(), ix, iy, x, copy(y), 1.0, 2.0) ≈ OMEinsum.loop_einsum(EinCode((ix,),iy), (x,), size_dict) + 2y
+    @test unary_einsum!(Diag(), ix, iy, x, copy(y), 2.0, 3.0) ≈ 2 * OMEinsum.loop_einsum(EinCode((ix,),iy), (x,), size_dict) + 3y
 end
 
 @testset "Repeat" begin