diff --git a/src/TimeModeling/Preconditioners/DataPreconditioners.jl b/src/TimeModeling/Preconditioners/DataPreconditioners.jl
index 31d562e03..3f50600ec 100644
--- a/src/TimeModeling/Preconditioners/DataPreconditioners.jl
+++ b/src/TimeModeling/Preconditioners/DataPreconditioners.jl
@@ -337,7 +337,6 @@ function matvec(D::TimeGain{T, K}, x::Array{T}) where {T, K}
     xr = reshape(x, D.recGeom)
     # make time^K
     timek = (D.recGeom.taxis[1]).^K
-    out.data[s] .= timek .* x.data[s]
     out = timek .* xr
     return reshape(out, size(x))
 end
diff --git a/test/test_preconditioners.jl b/test/test_preconditioners.jl
index 6f096cd73..ea199feb7 100644
--- a/test/test_preconditioners.jl
+++ b/test/test_preconditioners.jl
@@ -20,6 +20,7 @@ dm = model0.m - model.m
         F = judiFilter(recGeometry, .002, .030)
         Mdr = judiDataMute(srcGeometry, recGeometry; mode=:reflection)
         Mdt = judiDataMute(srcGeometry, recGeometry; mode=:turning)
+        Mdg = judiTimeGain(recGeometry, 2f0)
         order = .25f0
         Dt = judiTimeDerivative(recGeometry, order)
         It = judiTimeIntegration(recGeometry, order)
@@ -35,20 +36,23 @@ dm = model0.m - model.m
         dinv = Dt * It * dobs
         @test isapprox(dinv, dobs; atol=0f0, rtol=ftol)
 
+        # Time gain inverse is just 1/pow
+        @test inv(Mdg) == judiTimeGain(recGeometry, -2f0)
+
         # conj/transpose
-        for Pc in [F, Mdr, Mdt, Dt, It]
+        for Pc in [F, Mdr, Mdt, Mdg, Dt, It]
             @test conj(Pc) == Pc
             @test transpose(Pc) == Pc
         end
 
         # DataPrecon getindex
-        for Pc in [F, Mdr, Mdt, Dt, It]
+        for Pc in [F, Mdr, Mdt, Mdg, Dt, It]
             @test Pc[1] * dobs[1] == (Pc * dobs)[1]
             @test Pc[1] * dobs.data[1][:] ≈ (Pc * dobs).data[1][:] rtol=ftol
         end
 
         # Test in place DataPrecon
-        for Pc in [F, Mdr, Mdt, Dt, It]
+        for Pc in [F, Mdr, Mdt, Mdg, Dt, It]
             mul!(dobs_out, Pc, dobs)
             @test isapprox(dobs_out, Pc*dobs; rtol=ftol)
             mul!(dobs_out, Pc', dobs)
@@ -75,7 +79,7 @@ dm = model0.m - model.m
 
         # test out-of-place
         dobs1 = deepcopy(dobs)
-        for Op in [F, F', Mdr , Mdr', Mdt, Mdt', Dt, Dt', It, It']
+        for Op in [F, F', Mdr , Mdr', Mdt, Mdt', Mdg, Mdg', Dt, Dt', It, It']
             m = Op*dobs 
             # Test that dobs wasn't modified
             @test isapprox(dobs, dobs1, rtol=eps())