diff --git a/metropolis/installer/main.go b/metropolis/installer/main.go
index 6313548..a35a734 100644
--- a/metropolis/installer/main.go
+++ b/metropolis/installer/main.go
@@ -89,6 +89,9 @@
 	// Use the partition's name to find and return the name of its parent
 	// device. It will be excluded from the list of suitable target devices.
 	srcDev, err := sysfs.ParentBlockDevice(espDev)
+	if err != nil{
+		return nil, fmt.Errorf("failed to fetch parent device: %w", err)
+	}
 	// Build the exclusion list containing forbidden handle prefixes.
 	exclude := []string{"dm-", "zram", "ram", "loop", srcDev}
 
diff --git a/metropolis/installer/test/main.go b/metropolis/installer/test/main.go
index 3c2460a..b2fb8dc 100644
--- a/metropolis/installer/test/main.go
+++ b/metropolis/installer/test/main.go
@@ -273,6 +273,9 @@
 	}
 	// Verify that GPT exists.
 	ti, err := storage.GetPartitionTable()
+	if err != nil {
+		t.Fatalf("Couldn't read the installer image partition table: %s", err)
+	}
 	if ti.Type() != "gpt" {
 		t.Error("Couldn't verify that the resulting node image contains a GPT.")
 	}