diff --git a/internal/flags/flags_test.go b/internal/flags/flags_test.go
new file mode 100644
index 0000000..ac57b30
--- /dev/null
+++ b/internal/flags/flags_test.go
@@ -0,0 +1,39 @@
+package flags
+
+import (
+	"os"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEnvConfig_Defaults(t *testing.T) {
+	cmd := new(cobra.Command)
+	SetDefaults()
+	RegisterDockerFlags(cmd)
+
+	err := EnvConfig(cmd)
+	require.NoError(t, err)
+
+	assert.Equal(t, "unix:///var/run/docker.sock", os.Getenv("DOCKER_HOST"))
+	assert.Equal(t, "", os.Getenv("DOCKER_TLS_VERIFY"))
+	assert.Equal(t, DockerAPIMinVersion, os.Getenv("DOCKER_API_VERSION"))
+}
+
+func TestEnvConfig_Custom(t *testing.T) {
+	cmd := new(cobra.Command)
+	SetDefaults()
+	RegisterDockerFlags(cmd)
+
+	err := cmd.ParseFlags([]string{"--host", "some-custom-docker-host", "--tlsverify", "--api-version", "1.99"})
+	require.NoError(t, err)
+
+	err = EnvConfig(cmd)
+	require.NoError(t, err)
+
+	assert.Equal(t, "some-custom-docker-host", os.Getenv("DOCKER_HOST"))
+	assert.Equal(t, "1", os.Getenv("DOCKER_TLS_VERIFY"))
+	assert.Equal(t, "1.99", os.Getenv("DOCKER_API_VERSION"))
+}