diff --git a/decor/any.go b/decor/any.go
index 1ab764a..23ad75e 100644
--- a/decor/any.go
+++ b/decor/any.go
@@ -1,4 +1,6 @@
 package decor
+
+var _ Decorator = (*any)(nil)
 
 // Any decorator displays text, that can be changed during decorator's
 // lifetime via provided DecorFunc.
diff --git a/decor/eta.go b/decor/eta.go
index 691f8b7..3594e01 100644
--- a/decor/eta.go
+++ b/decor/eta.go
@@ -6,6 +6,13 @@
 	"time"
 
 	"github.com/VividCortex/ewma"
+)
+
+var (
+	_ Decorator        = (*movingAverageETA)(nil)
+	_ EwmaDecorator    = (*movingAverageETA)(nil)
+	_ Decorator        = (*averageETA)(nil)
+	_ AverageDecorator = (*averageETA)(nil)
 )
 
 // TimeNormalizer interface. Implementors could be passed into
diff --git a/decor/merge.go b/decor/merge.go
index a30b785..aa0fcb9 100644
--- a/decor/merge.go
+++ b/decor/merge.go
@@ -5,6 +5,12 @@
 
 	"github.com/acarl005/stripansi"
 	"github.com/mattn/go-runewidth"
+)
+
+var (
+	_ Decorator = (*mergeDecorator)(nil)
+	_ Wrapper   = (*mergeDecorator)(nil)
+	_ Decorator = (*placeHolderDecorator)(nil)
 )
 
 // Merge wraps its decorator argument with intention to sync width
diff --git a/decor/on_abort.go b/decor/on_abort.go
index e36a63c..862ae33 100644
--- a/decor/on_abort.go
+++ b/decor/on_abort.go
@@ -1,4 +1,9 @@
 package decor
+
+var (
+	_ Decorator = (*onAbortWrapper)(nil)
+	_ Wrapper   = (*onAbortWrapper)(nil)
+)
 
 // OnAbort returns decorator, which wraps provided decorator with sole
 // purpose to display provided message on abort event. It has no effect
diff --git a/decor/on_complete.go b/decor/on_complete.go
index 837d067..6ee9268 100644
--- a/decor/on_complete.go
+++ b/decor/on_complete.go
@@ -1,4 +1,9 @@
 package decor
+
+var (
+	_ Decorator = (*onCompleteWrapper)(nil)
+	_ Wrapper   = (*onCompleteWrapper)(nil)
+)
 
 // OnComplete returns decorator, which wraps provided decorator with
 // sole purpose to display provided message on complete event.
diff --git a/decor/speed.go b/decor/speed.go
index 47d54dc..3ddabb2 100644
--- a/decor/speed.go
+++ b/decor/speed.go
@@ -6,6 +6,13 @@
 	"time"
 
 	"github.com/VividCortex/ewma"
+)
+
+var (
+	_ Decorator        = (*movingAverageSpeed)(nil)
+	_ EwmaDecorator    = (*movingAverageSpeed)(nil)
+	_ Decorator        = (*averageSpeed)(nil)
+	_ AverageDecorator = (*averageSpeed)(nil)
 )
 
 // FmtAsSpeed adds "/s" to the end of the input formatter. To be