diff --git a/go.mod b/go.mod
index feca967..077799b 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module github.com/andygeiss/esp32-transpiler
 
-require github.com/andygeiss/assert v0.0.3
+go 1.12
+
+require github.com/andygeiss/assert v0.0.6
diff --git a/go.sum b/go.sum
index 9517c99..c461b8c 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-github.com/andygeiss/assert v0.0.3 h1:PgY7eH+UaCvOzScsX3HGqNfCemkvpcNHQjwT2Dyq0sw=
-github.com/andygeiss/assert v0.0.3/go.mod h1:ztUvWrfUo43X0zMA1XfX8esn5Uavk6ANSKTT0w2qvAI=
+github.com/andygeiss/assert v0.0.6 h1:FyiAIudVwnxp55GIcNOaZ2ABr8n2RI9SXmaXG7+Y53o=
+github.com/andygeiss/assert v0.0.6/go.mod h1:ztUvWrfUo43X0zMA1XfX8esn5Uavk6ANSKTT0w2qvAI=
diff --git a/impl/transpile/transpile_test.go b/impl/transpile/transpile_test.go
index 8015f3e..31ab8b2 100644
--- a/impl/transpile/transpile_test.go
+++ b/impl/transpile/transpile_test.go
@@ -3,7 +3,6 @@ package transpile_test
 import (
 	"bytes"
 	"github.com/andygeiss/assert"
-	"github.com/andygeiss/assert/is"
 	"github.com/andygeiss/esp32-transpiler/api/worker"
 	"github.com/andygeiss/esp32-transpiler/impl/transpile"
 	"io"
@@ -32,5 +31,5 @@ func TestTranspileErrorShouldBeNil(t *testing.T) {
 	worker := &mockupWorker{&in, &out}
 	trans := transpile.NewTranspiler(worker)
 	err := trans.Transpile()
-	assert.That(t, err, is.Equal(nil))
+	assert.That(t, err, nil)
 }
diff --git a/impl/worker/worker_test.go b/impl/worker/worker_test.go
index 75ed639..2865f92 100644
--- a/impl/worker/worker_test.go
+++ b/impl/worker/worker_test.go
@@ -3,7 +3,6 @@ package worker_test
 import (
 	"bytes"
 	"github.com/andygeiss/assert"
-	"github.com/andygeiss/assert/is"
 	"github.com/andygeiss/esp32-transpiler/impl/worker"
 	"strings"
 	"testing"
@@ -24,10 +23,10 @@ func Validate(source, expected string, t *testing.T) {
 	var in, out bytes.Buffer
 	in.WriteString(source)
 	wrk := worker.NewWorker(&in, &out, worker.NewMapping())
-	assert.That(t, wrk.Start(), is.Equal(nil))
+	assert.That(t, wrk.Start(), nil)
 	code := out.String()
 	tcode, texpected := Trim(code), Trim(expected)
-	assert.That(t, tcode, is.Equal(texpected))
+	assert.That(t, tcode, texpected)
 }
 
 func Test_Empty_Package(t *testing.T) {