diff --git a/src/distributions/wishart.jl b/src/distributions/wishart.jl
index 773166a4..1fcbb238 100644
--- a/src/distributions/wishart.jl
+++ b/src/distributions/wishart.jl
@@ -203,6 +203,12 @@ function BayesBase.prod(::PreserveTypeProd{Distribution}, left::WishartFast, rig
     return WishartFast(df, invV)
 end
 
+BayesBase.default_prod_rule(::Type{<:Wishart}, ::Type{<:WishartFast}) = PreserveTypeProd(Distribution)
+
+function BayesBase.prod(::PreserveTypeProd{Distribution}, left::Wishart, right::WishartFast)
+    return prod(PreserveTypeProd(Distribution), convert(WishartFast, left), right)
+end
+
 function BayesBase.insupport(ef::ExponentialFamilyDistribution{WishartFast}, x::Matrix)
     return size(getindex(unpack_parameters(ef), 2)) == size(x) && isposdef(x)
 end
diff --git a/src/distributions/wishart_inverse.jl b/src/distributions/wishart_inverse.jl
index 4cb80207..6c308999 100644
--- a/src/distributions/wishart_inverse.jl
+++ b/src/distributions/wishart_inverse.jl
@@ -225,6 +225,18 @@ function BayesBase.prod(::PreserveTypeProd{Distribution}, left::InverseWishartFa
     return InverseWishartFast(df, V)
 end
 
+BayesBase.default_prod_rule(::Type{<:InverseWishart}, ::Type{<:InverseWishartFast}) = PreserveTypeProd(Distribution)
+
+function BayesBase.prod(::PreserveTypeProd{Distribution}, left::InverseWishart, right::InverseWishartFast)
+    return prod(PreserveTypeProd(Distribution), convert(InverseWishartFast, left), right)
+end
+
+BayesBase.default_prod_rule(::Type{<:InverseWishart}, ::Type{<:InverseWishart}) = PreserveTypeProd(Distribution)
+
+function BayesBase.prod(::PreserveTypeProd{Distribution}, left::InverseWishart, right::InverseWishart)
+    return prod(PreserveTypeProd(Distribution), convert(InverseWishartFast, left), convert(InverseWishartFast, right))
+end
+
 function BayesBase.insupport(ef::ExponentialFamilyDistribution{InverseWishartFast}, x::Matrix)
     return size(getindex(unpack_parameters(ef), 2)) == size(x) && isposdef(x)
 end
diff --git a/test/distributions/wishart_inverse_tests.jl b/test/distributions/wishart_inverse_tests.jl
index 9d76f41b..3c586004 100644
--- a/test/distributions/wishart_inverse_tests.jl
+++ b/test/distributions/wishart_inverse_tests.jl
@@ -228,3 +228,37 @@ end
         end
     end
 end
+
+@testitem "InverseWishart: prod between InverseWishart and InverseWishartFast" begin
+    include("distributions_setuptests.jl")
+
+    import ExponentialFamily: InverseWishartFast
+    import Distributions: InverseWishart
+
+    for Sleft in rand(InverseWishart(10, Array(Eye(2))), 2), Sright in rand(InverseWishart(10, Array(Eye(2))), 2), νright in (6, 7), νleft in (4, 5)
+        let left = InverseWishart(νleft, Sleft), right = InverseWishart(νleft, Sleft), right_fast = convert(InverseWishartFast, right)
+            # Test commutativity of the product
+            prod_result1 = prod(PreserveTypeProd(Distribution), left, right_fast)
+            prod_result2 = prod(PreserveTypeProd(Distribution), right_fast, left)
+            
+            @test prod_result1.ν ≈ prod_result2.ν
+            @test prod_result1.S ≈ prod_result2.S
+            
+            # Test that the product preserves type
+            @test prod_result1 isa InverseWishartFast
+            @test prod_result2 isa InverseWishartFast
+
+            # prod stays if we convert fisrt and then do product
+            left_fast = convert(InverseWishartFast, left)
+            prod_fast = prod(ClosedProd(), left_fast, right_fast)
+
+            @test prod_fast.ν ≈ prod_result1.ν
+            @test prod_fast.S ≈ prod_result2.S
+
+            # prod for Inverse Wishart is defenied 
+            prod_result_not_fast = prod(PreserveTypeProd(Distribution), left, right)
+            @test prod_result_not_fast.ν ≈ prod_result1.ν
+            @test prod_result_not_fast.S ≈ prod_result1.S
+        end
+    end
+end
diff --git a/test/distributions/wishart_tests.jl b/test/distributions/wishart_tests.jl
index 33e90f71..fca2acbc 100644
--- a/test/distributions/wishart_tests.jl
+++ b/test/distributions/wishart_tests.jl
@@ -131,3 +131,33 @@ end
         end
     end
 end
+
+@testitem "Wishart: prod between Wishart and WishartFast" begin
+    include("distributions_setuptests.jl")
+
+    import ExponentialFamily: WishartFast
+    import Distributions: Wishart
+
+    for Sleft in rand(Wishart(10, Array(Eye(2))), 2), Sright in rand(Wishart(10, Array(Eye(2))), 2), νright in (6, 7), νleft in (4, 5)
+        let left = Wishart(νleft, Sleft), right = WishartFast(νright, Sright)
+            # Test commutativity of the product
+            prod_result1 = prod(PreserveTypeProd(Distribution), left, right)
+            prod_result2 = prod(PreserveTypeProd(Distribution), right, left)
+            
+            @test prod_result1.ν ≈ prod_result2.ν
+            @test prod_result1.invS ≈ prod_result2.invS
+            
+            # Test that the product preserves type
+            @test prod_result1 isa WishartFast
+            @test prod_result2 isa WishartFast
+
+            # prod stays the same if we convert fisrt and then do product
+            left_fast = convert(WishartFast, left)
+            prod_fast = prod(ClosedProd(), left_fast, right)
+
+            @test prod_fast.ν ≈ prod_result1.ν
+            @test prod_fast.invS ≈ prod_result2.invS
+        end
+    end
+end
+