diff --git a/Project.toml b/Project.toml
index 889b85f..8366021 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "IterationControl"
 uuid = "b3c1a2ee-3fec-4384-bf48-272ea71de57c"
 authors = ["Anthony D. Blaom <anthony.blaom@gmail.com>"]
-version = "0.5.2"
+version = "0.5.3"
 
 [deps]
 EarlyStopping = "792122b4-ca99-40de-a6bc-6742525f08b6"
diff --git a/src/controls.jl b/src/controls.jl
index 5231860..aee2699 100644
--- a/src/controls.jl
+++ b/src/controls.jl
@@ -152,11 +152,11 @@ struct Callback{F<:Function}
 end
 
 # constructor:
-Callback(f::Function;
+Callback(; f=identity,
          stop_if_true=false,
          stop_message=nothing,
          raw=false) = Callback(f, stop_if_true, stop_message, raw)
-Callback(; f=identity, kwargs...) = Callback(f, kwargs...)
+Callback(f; kwargs...) = Callback(; f=f, kwargs...)
 
 @create_docs(Callback,
              header="Callback(f=_->nothing, stop_if_true=false, "*
@@ -275,10 +275,10 @@ struct WithLossDo{F<:Function}
 end
 
 # constructor:
-WithLossDo(f::Function;
-     stop_if_true=false,
-     stop_message=nothing) = WithLossDo(f, stop_if_true, stop_message)
-WithLossDo(; f=x->@info("loss: $x"), kwargs...) = WithLossDo(f, kwargs...)
+WithLossDo(; f=x->@info("loss: $x"),
+           stop_if_true=false,
+           stop_message=nothing) = WithLossDo(f, stop_if_true, stop_message)
+WithLossDo(f; kwargs...) = WithLossDo(; f=f, kwargs...)
 
 @create_docs(WithLossDo,
              header="WithLossDo(f=x->@info(\"loss: \$x\"), "*
@@ -330,11 +330,12 @@ struct WithTrainingLossesDo{F<:Function}
 end
 
 # constructor:
-WithTrainingLossesDo(f::Function;
-     stop_if_true=false,
-     stop_message=nothing) = WithTrainingLossesDo(f, stop_if_true, stop_message)
-WithTrainingLossesDo(; f=v->@info("training: $v"), kwargs...) =
-    WithTrainingLossesDo(f, kwargs...)
+WithTrainingLossesDo(; f=v->@info("training: $v"),
+                     stop_if_true=false,
+                     stop_message=nothing) =
+                         WithTrainingLossesDo(f, stop_if_true, stop_message)
+WithTrainingLossesDo(f; kwargs...) =
+    WithTrainingLossesDo(; f=f, kwargs...)
 
 @create_docs(WithTrainingLossesDo,
              header="WithTrainingLossesDo(f=v->@info(\"training: \$v\"), "*
@@ -388,10 +389,10 @@ struct WithNumberDo{F<:Function}
 end
 
 # constructor:
-WithNumberDo(f::Function;
-     stop_if_true=false,
-     stop_message=nothing) = WithNumberDo(f, stop_if_true, stop_message)
-WithNumberDo(; f=n->@info("number: $n"), kwargs...) = WithNumberDo(f, kwargs...)
+WithNumberDo(; f=n->@info("number: $n"),
+             stop_if_true=false,
+             stop_message=nothing) = WithNumberDo(f, stop_if_true, stop_message)
+WithNumberDo(f; kwargs...) = WithNumberDo(; f=f, kwargs...)
 
 @create_docs(WithNumberDo,
              header="WithNumberDo(f=n->@info(\"number: \$n\"), "*
diff --git a/test/controls.jl b/test/controls.jl
index 319478c..8867e48 100644
--- a/test/controls.jl
+++ b/test/controls.jl
@@ -441,3 +441,28 @@ end
     @test length(losses) == length(data) + 1
     @test loss(model) > 0.01
 end
+
+@testset "constructors #55" begin
+    for Control in [WithTrainingLossesDo,
+                    Callback,
+                    WithLossDo,
+                    WithNumberDo]
+        g(x) = true
+
+        c = Control(g)
+        @test c.f == g
+        @test !c.stop_if_true
+
+        c= Control(g, stop_if_true=true)
+        @test c.f == g
+        @test c.stop_if_true
+
+        c= Control(f=g)
+        @test c.f == g
+        @test !c.stop_if_true
+
+        c= Control(f=g, stop_if_true=true)
+        @test c.f == g
+        @test c.stop_if_true
+    end
+end