diff --git a/Project.toml b/Project.toml
index 6f0f748..7d47946 100644
--- a/Project.toml
+++ b/Project.toml
@@ -4,13 +4,14 @@ authors = ["Krisztián Schaffer"]
 version = "0.4.2"
 
 [deps]
+InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 
 [compat]
 julia = "1.4"
 
 [extras]
-Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
 test = ["Test", "Random"]
diff --git a/src/deps.jl b/src/deps.jl
index 04d4fa0..863db65 100644
--- a/src/deps.jl
+++ b/src/deps.jl
@@ -1,15 +1,32 @@
+using InteractiveUtils
+
 struct RegisteredPlugin
     type::Type
-    deps::Vector{Type}
+    deps::Vector{<:Type}
 end
 
 const registry = IdDict{Type,RegisteredPlugin}()
 
-function register(plugin::Type, deps::Vector{<:Type} = Type[]) # !?
-    registry[plugin] = RegisteredPlugin(plugin, deps)
+function register(plugin::Type, dependencies = deps(plugin))
+    registry[plugin] = RegisteredPlugin(plugin, dependencies)
     return nothing
 end
 
+deps(t) = Type[]
+
+function autoregister(base=Plugin)
+    for t in subtypes(base) # TODO subtypes is extremely slow
+        if isconcretetype(t)
+            if !haskey(registry, t)
+                @debug "Auto-registering plugin type $t"
+                register(t)
+            end
+        else
+            autoregister(t)
+        end
+    end
+end
+
 # t1 implements t2 or
 # t1 is an interface that is more specific than t2, or
 # t1 and t2 are implementations and t1's direct interface
@@ -41,12 +58,12 @@ getplugin(p) = error("The $(typeof(p)) is instantiated. Please provide a type in
 
 allplugins() = values(registry)
 plugintypes(plugins) = map(p->p.type, plugins)
-deps(plugins) = unique(Iterators.flatten(map(p->p.deps, plugins)))::Vector{Type}
+plugindeps(plugins) = unique(Iterators.flatten(map(p->p.deps, plugins)))
 findimplementation(req, impls) = findfirst(t -> t <: req, impls)
 
 function missingdeps(plugins, dependencies)
     deptypes = plugintypes(dependencies)
-    return filter(deps(plugins)) do p
+    return filter(plugindeps(plugins)) do p
         isnothing(findimplementation(p, deptypes))
     end
 end
diff --git a/test/deps.jl b/test/deps.jl
index 489827a..a03c55f 100644
--- a/test/deps.jl
+++ b/test/deps.jl
@@ -68,39 +68,41 @@ A more realistic example is a small module structure with complex dependencies.
 Instantiated implementations receive instances of their dependencies as arguments
 to the constructor, and may also receive options through kwargs.
 """
-abstract type MI1 end
+abstract type MI1 <: Plugin  end
 struct MImpl1 <: MI1
     x1
     x2
     MImpl1(; x1=nothing, x2=nothing, options...) = new(x1, x2)
 end
 
-abstract type MI2 end
+abstract type MI2 <: Plugin  end
 struct MImpl2 <: MI2
     MImpl2(::MI1; options...) = new()
 end
+Plugins.deps(::Type{MImpl2}) = [MImpl1]
 
-abstract type MI3 end
+abstract type MI3 <: Plugin  end
 struct MImpl3 <: MI3
     MImpl3(::MI1; options...) = new()
 end
 
-abstract type MI4 end
+abstract type MI4 <: Plugin  end
 struct MImpl4 <: MI4
     MImpl4(::MI1, ::MI2; options...) = new()
 end
 
-abstract type MI5 end
+abstract type MI5 <: Plugin end
 struct MImpl5 <: MI5
     MImpl5(::MI4, ::MI2; options...) = new()
 end
+Plugins.deps(::Type{MImpl5}) = [MImpl4, MI2]
 
 @testset "Dependency hierarchies are tracked" begin
     Plugins.register(MImpl1)
-    Plugins.register(MImpl2, [MImpl1])
+    Plugins.register(MImpl2)
     Plugins.register(MImpl3, [MI2])
     Plugins.register(MImpl4, [MI1, MI2])
-    Plugins.register(MImpl5, [MImpl4, MI2])
+    Plugins.autoregister() # MImpl5
     @test sort(Plugins.instantiation_order([MI1, MI2])) == sort([MImpl1, MImpl2])
     @test sort(Plugins.instantiation_order([MI1, MI3])) == sort([MImpl1, MImpl2, MImpl3])
     @test sort(Plugins.instantiation_order([MImpl3, MImpl1])) == sort([MImpl1, MImpl2, MImpl3])