diff --git a/Project.toml b/Project.toml
index c368ff0..152acd7 100644
--- a/Project.toml
+++ b/Project.toml
@@ -4,8 +4,18 @@ authors = ["Miles Lucas <mdlucas@hawaii.edu> and contributors"]
 version = "0.1.0"
 
 [deps]
+TestItemRunner = "f8b46487-2199-4994-9208-9a1283c18c0a"
+
+[weakdeps]
+DynamicQuantities = "06fc5a27-2a28-4c7c-a15d-362465fb6821"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 
+[extensions]
+PlanckDynamicQuantitiesExt = "DynamicQuantities"
+PlanckUnitfulExt = "Unitful"
+
 [compat]
+DynamicQuantities = "1, 1.8"
+TestItemRunner = "1.1.0"
 Unitful = "1"
-julia = "1.6"
+julia = "1.10"
diff --git a/ext/PlanckDynamicQuantitiesExt.jl b/ext/PlanckDynamicQuantitiesExt.jl
new file mode 100644
index 0000000..2ccf328
--- /dev/null
+++ b/ext/PlanckDynamicQuantitiesExt.jl
@@ -0,0 +1,34 @@
+module PlanckDynamicQuantitiesExt
+    import Planck
+
+    using DynamicQuantities: UnionAbstractQuantity, Dimensions, dimension, uexpand
+    using DynamicQuantities.Constants: h, c, k_B
+
+    using TestItemRunner: @testitem
+
+    isfreq(q::UnionAbstractQuantity) = (dimension ∘ uexpand)(q) == Dimensions(time=-1)
+    islength(q::UnionAbstractQuantity) = (dimension ∘ uexpand)(q) == Dimensions(length=1)
+
+    function Planck.blackbody(q::UnionAbstractQuantity, T)
+        if isfreq(q)
+            return 2 * h * q^3 / c^2 / expm1(h * q / (k_B * T))
+        end
+        if islength(q)
+            return 2 * h * c^2 / q^5 / expm1(h * c / (q * k_B * T))
+        end
+    end
+
+    @testitem "Consistent unit conversions" begin
+        using Planck, DynamicQuantities
+
+        @test (ustrip ∘ blackbody)(545us"nm", 6000u"K") ≈ blackbody(545e-9, 6000)
+        @test (ustrip ∘ blackbody)(500_000us"GHz", 6000u"K") ≈ 3.441e-8 rtol=1e-3
+    end
+
+    @testitem "Known temperatures" begin
+        using Planck, DynamicQuantities
+
+        @test blackbody(545us"nm", 6000u"K") ≈ 3.079e13u"W/m^3" rtol=1e-3
+        @test blackbody(500_000u"GHz", 6000u"K") ≈ 3.441e-8u"W/m^2/Hz" rtol=1e-3
+    end
+end # end
diff --git a/ext/PlanckUnitfulExt.jl b/ext/PlanckUnitfulExt.jl
new file mode 100644
index 0000000..c4c452f
--- /dev/null
+++ b/ext/PlanckUnitfulExt.jl
@@ -0,0 +1,31 @@
+module PlanckUnitfulExt
+    import Planck
+
+    using Unitful: AbstractQuantity
+    using Unitful: 𝐋, 𝐓
+    using Unitful: h, c0, k
+
+    using TestItemRunner: @testitem
+
+    function Planck.blackbody(ν::AbstractQuantity{V,inv(𝐓)}, T) where V
+        2 * h * ν^3 / c0^2 / expm1(h * ν / (k * T))
+    end
+
+    function Planck.blackbody(λ::AbstractQuantity{V,𝐋}, T) where V
+        2 * h * c0^2 / λ^5 / expm1(h * c0 / (λ * k * T))
+    end
+
+    @testitem "Consistent unit conversions" begin
+        using Planck, Unitful
+
+        @test ustrip(u"W/m^3", blackbody(545u"nm", 6000u"K")) ≈ blackbody(545e-9, 6000)
+        @test ustrip(u"W/m^2/Hz", blackbody(500u"THz", 6000u"K")) ≈ 3.441e-8 rtol=1e-3
+    end
+
+    @testitem "Known temperatures" begin
+        using Planck, Unitful
+
+        @test blackbody(545u"nm", 6000u"K") ≈ 3.079e13u"W/m^3" rtol=1e-3
+        @test blackbody(500u"THz", 6000u"K") ≈ 3.441e-8u"W/m^2/Hz" rtol=1e-3
+    end
+end # end
diff --git a/src/Planck.jl b/src/Planck.jl
index a985cca..731f5bb 100644
--- a/src/Planck.jl
+++ b/src/Planck.jl
@@ -1,17 +1,13 @@
 module Planck
 
-using Unitful
-using Unitful: AbstractQuantity
-using Unitful: 𝐋, 𝐓
-using Unitful: h, c0, k
-
 export blackbody
 
-# constants in SI units
-const _h = ustrip(u"J*s", h)
-const _c0 = ustrip(u"m/s", c0)
-const _k = ustrip(u"J/K", k)
+using TestItemRunner: @testitem
 
+# constants in SI units
+const _h = 6.62607015e-34
+const _c0 = 299792458
+const _k = 1.380649e-23
 
 """
     blackbody([OT], x, T)
@@ -51,18 +47,18 @@ julia> blackbody(u"erg/s/cm^2/nm/sr", 600u"nm", 5850u"K")
 """
 blackbody(OT, x, T) = OT(blackbody(x, T))
 
-function blackbody(ν::AbstractQuantity{V,inv(𝐓)}, T) where V
-    2 * h * ν^3 / c0^2 / expm1(h * ν / (k * T))
-end
-
-function blackbody(λ::AbstractQuantity{V,𝐋}, T) where V
-    2 * h * c0^2 / λ^5 / expm1(h * c0 / (λ * k * T))
-end
 
 # SI (meters, Kelvin)
 function blackbody(λ, T)
     2 * _h * _c0^2 / λ^5 / expm1(_h * _c0 / (λ * _k * T)) # W / m^3
 end
 
+@testitem "Known temperatures" begin
+    using Planck, Unitful
 
+    @test blackbody(545e-9, 6000) ≈ 3.079e13 rtol=1e-3
+    @test blackbody(Float32, 545e-9, 6000) ≈ 3.079f13 rtol=1f-3
 end
+
+
+end # end
diff --git a/test/Project.toml b/test/Project.toml
index 0ff3cec..c28b735 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -1,3 +1,9 @@
 [deps]
+DynamicQuantities = "06fc5a27-2a28-4c7c-a15d-362465fb6821"
+Planck = "49ffdefc-b0d8-4915-a1d4-43900e16f762"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+TestItemRunner = "f8b46487-2199-4994-9208-9a1283c18c0a"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
+
+[sources]
+Planck = {path = ".."}
diff --git a/test/runtests.jl b/test/runtests.jl
index 0cd421d..501770d 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,17 +1,3 @@
-using Planck
-using Test
-using Unitful
+using TestItemRunner
 
-@testset "Planck.jl" begin
-    @testset "Consistent unit conversions" begin
-        @test ustrip(u"W/m^3", blackbody(545u"nm", 6000u"K")) ≈ blackbody(545e-9, 6000)
-        @test ustrip(u"W/m^2/Hz", blackbody(500u"THz", 6000u"K")) ≈ 3.441e-8 rtol=1e-3
-    end
-    @testset "Known temperatures" begin
-        @test blackbody(545e-9, 6000) ≈ 3.079e13 rtol=1e-3
-        @test blackbody(Float32, 545e-9, 6000) ≈ 3.079f13 rtol=1f-3
-
-        @test blackbody(545u"nm", 6000u"K") ≈ 3.079e13u"W/m^3" rtol=1e-3
-        @test blackbody(500u"THz", 6000u"K") ≈ 3.441e-8u"W/m^2/Hz" rtol=1e-3
-    end
-end
+@run_package_tests filter=ti -> occursin("Planck", ti.filename) verbose=true