diff --git a/pkg/build/workflow.go b/pkg/build/workflow.go
index aceb3b7..20ecaa8 100644
--- a/pkg/build/workflow.go
+++ b/pkg/build/workflow.go
@@ -28,11 +28,15 @@ const DefaultReleaseWorkflowFileName = "release.yml"
 // build.WriteReleaseWorkflow(io.Local, "ci/release.yml")                          // writes ./ci/release.yml under the project root
 // build.WriteReleaseWorkflow(io.Local, "/tmp/repo/.github/workflows/release.yml") // writes the absolute path unchanged
 func WriteReleaseWorkflow(medium io_interface.Medium, outputPath string) error {
+	if medium == nil {
+		return coreerr.E("build.WriteReleaseWorkflow", "filesystem medium is required", nil)
+	}
+
 	if outputPath == "" {
 		outputPath = DefaultReleaseWorkflowPath
 	}
 
-	if medium != nil && (isDirectoryLikePath(outputPath) || medium.IsDir(outputPath)) {
+	if isDirectoryLikePath(outputPath) || medium.IsDir(outputPath) {
 		outputPath = ax.Join(outputPath, DefaultReleaseWorkflowFileName)
 	}
 
diff --git a/pkg/build/workflow_test.go b/pkg/build/workflow_test.go
index b5997c3..e194071 100644
--- a/pkg/build/workflow_test.go
+++ b/pkg/build/workflow_test.go
@@ -88,6 +88,14 @@ func TestWorkflow_WriteReleaseWorkflow_Good(t *testing.T) {
 	})
 }
 
+func TestWorkflow_WriteReleaseWorkflow_Bad(t *testing.T) {
+	t.Run("rejects a nil filesystem medium", func(t *testing.T) {
+		err := WriteReleaseWorkflow(nil, "")
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "filesystem medium is required")
+	})
+}
+
 func TestWorkflow_ReleaseWorkflowPath_Good(t *testing.T) {
 	assert.Equal(t, "/tmp/project/.github/workflows/release.yml", ReleaseWorkflowPath("/tmp/project"))
 }