diff --git a/database/tbcd/level/headercache_test.go b/database/tbcd/level/headercache_test.go
new file mode 100644
index 00000000..60a3ba9d
--- /dev/null
+++ b/database/tbcd/level/headercache_test.go
@@ -0,0 +1,47 @@
+package level
+
+import (
+	"testing"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/hemilabs/heminetwork/database/tbcd"
+)
+
+func intHash(b int) chainhash.Hash {
+	return chainhash.Hash{byte(b)}
+}
+
+func TestHC(t *testing.T) {
+
+	size := 10
+	l := lowIQMapNew(size)
+
+	hs := intHash(0)
+	for range 2 {
+		l.Put(&tbcd.BlockHeader{
+			Hash: hs,
+		})
+	}
+	if len(l.m) > 1 {
+		t.Fatalf("duplicate headers not excluded by hash")
+	}
+
+	if _, ok := l.Get(&hs); !ok {
+		t.Fatalf("failed to retrieve header present in map")
+	}
+
+	hs = intHash(1)
+	if _, ok := l.Get(&hs); ok {
+		t.Fatalf("invalid header retrieved from Map")
+	}
+
+	for k := range size + 5 {
+		l.Put(&tbcd.BlockHeader{
+			Hash: intHash(k),
+		})
+	}
+	if len(l.m) > l.count {
+		t.Fatalf("map size exceeded bounds (failed eviction)")
+	}
+
+}