diff --git a/internal/zencmd/window_unix_test.go b/internal/zencmd/window_unix_test.go
new file mode 100644
index 0000000..a0769f7
--- /dev/null
+++ b/internal/zencmd/window_unix_test.go
@@ -0,0 +1,31 @@
+//go:build !windows && !darwin
+
+package zencmd
+
+import (
+	"os"
+	"testing"
+)
+
+func Test_getPidToPpidMap(t *testing.T) {
+	got, err := getPidToPpidMap()
+	if err != nil {
+		t.Fatalf("getPidToPpidMap() error = %v", err)
+	}
+	if ppid := got[os.Getpid()]; ppid != os.Getppid() {
+		t.Errorf("getPidToPpidMap()[%d] = %d; want %d", os.Getpid(), ppid, os.Getppid())
+	}
+}
+
+func Test_getPidToWindowMap(t *testing.T) {
+	got, err := getPidToWindowMap()
+	if err != nil {
+		if os.Getenv("DISPLAY") == "" {
+			t.Skip("skipping:", err)
+		}
+		t.Fatalf("getPidToWindowMap() error = %v", err)
+	}
+	if len(got) == 0 {
+		t.Errorf("getPidToWindowMap() %v", got)
+	}
+}