diff --git a/Makefile b/Makefile
index 3863e60b66..699af109f7 100644
--- a/Makefile
+++ b/Makefile
@@ -1341,6 +1341,7 @@ UNIT_TEST_PROGRAMS += t-oidtree
 UNIT_TEST_PROGRAMS += t-prio-queue
 UNIT_TEST_PROGRAMS += t-reftable-basics
 UNIT_TEST_PROGRAMS += t-reftable-merged
+UNIT_TEST_PROGRAMS += t-reftable-pq
 UNIT_TEST_PROGRAMS += t-reftable-record
 UNIT_TEST_PROGRAMS += t-strbuf
 UNIT_TEST_PROGRAMS += t-strcmp-offset
@@ -2681,7 +2682,6 @@ REFTABLE_OBJS += reftable/writer.o
 
 REFTABLE_TEST_OBJS += reftable/block_test.o
 REFTABLE_TEST_OBJS += reftable/dump.o
-REFTABLE_TEST_OBJS += reftable/pq_test.o
 REFTABLE_TEST_OBJS += reftable/readwrite_test.o
 REFTABLE_TEST_OBJS += reftable/stack_test.o
 REFTABLE_TEST_OBJS += reftable/test_framework.o
diff --git a/reftable/pq.c b/reftable/pq.c
index 7fb45d8c60..2b5b7d1c0e 100644
--- a/reftable/pq.c
+++ b/reftable/pq.c
@@ -22,27 +22,21 @@ int pq_less(struct pq_entry *a, struct pq_entry *b)
 
 struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq)
 {
-	int i = 0;
+	size_t i = 0;
 	struct pq_entry e = pq->heap[0];
 	pq->heap[0] = pq->heap[pq->len - 1];
 	pq->len--;
 
-	i = 0;
 	while (i < pq->len) {
-		int min = i;
-		int j = 2 * i + 1;
-		int k = 2 * i + 2;
-		if (j < pq->len && pq_less(&pq->heap[j], &pq->heap[i])) {
+		size_t min = i;
+		size_t j = 2 * i + 1;
+		size_t k = 2 * i + 2;
+		if (j < pq->len && pq_less(&pq->heap[j], &pq->heap[i]))
 			min = j;
-		}
-		if (k < pq->len && pq_less(&pq->heap[k], &pq->heap[min])) {
+		if (k < pq->len && pq_less(&pq->heap[k], &pq->heap[min]))
 			min = k;
-		}
-
-		if (min == i) {
+		if (min == i)
 			break;
-		}
-
 		SWAP(pq->heap[i], pq->heap[min]);
 		i = min;
 	}
@@ -52,20 +46,17 @@ struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq)
 
 void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry *e)
 {
-	int i = 0;
+	size_t i = 0;
 
 	REFTABLE_ALLOC_GROW(pq->heap, pq->len + 1, pq->cap);
 	pq->heap[pq->len++] = *e;
 
 	i = pq->len - 1;
 	while (i > 0) {
-		int j = (i - 1) / 2;
-		if (pq_less(&pq->heap[j], &pq->heap[i])) {
+		size_t j = (i - 1) / 2;
+		if (pq_less(&pq->heap[j], &pq->heap[i]))
 			break;
-		}
-
 		SWAP(pq->heap[j], pq->heap[i]);
-
 		i = j;
 	}
 }
diff --git a/reftable/pq.h b/reftable/pq.h
index f796c23179..707bd26767 100644
--- a/reftable/pq.h
+++ b/reftable/pq.h
@@ -22,7 +22,6 @@ struct merged_iter_pqueue {
 	size_t cap;
 };
 
-void merged_iter_pqueue_check(struct merged_iter_pqueue pq);
 struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq);
 void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry *e);
 void merged_iter_pqueue_release(struct merged_iter_pqueue *pq);
diff --git a/reftable/pq_test.c b/reftable/pq_test.c
deleted file mode 100644
index b7d3c80cc7..0000000000
--- a/reftable/pq_test.c
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
-Copyright 2020 Google LLC
-
-Use of this source code is governed by a BSD-style
-license that can be found in the LICENSE file or at
-https://developers.google.com/open-source/licenses/bsd
-*/
-
-#include "system.h"
-
-#include "basics.h"
-#include "constants.h"
-#include "pq.h"
-#include "record.h"
-#include "reftable-tests.h"
-#include "test_framework.h"
-
-void merged_iter_pqueue_check(struct merged_iter_pqueue pq)
-{
-	int i;
-	for (i = 1; i < pq.len; i++) {
-		int parent = (i - 1) / 2;
-
-		EXPECT(pq_less(&pq.heap[parent], &pq.heap[i]));
-	}
-}
-
-static void test_pq(void)
-{
-	struct merged_iter_pqueue pq = { NULL };
-	struct reftable_record recs[54];
-	int N = ARRAY_SIZE(recs) - 1, i;
-	char *last = NULL;
-
-	for (i = 0; i < N; i++) {
-		struct strbuf refname = STRBUF_INIT;
-		strbuf_addf(&refname, "%02d", i);
-
-		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
-		recs[i].u.ref.refname = strbuf_detach(&refname, NULL);
-	}
-
-	i = 1;
-	do {
-		struct pq_entry e = {
-			.rec = &recs[i],
-		};
-
-		merged_iter_pqueue_add(&pq, &e);
-		merged_iter_pqueue_check(pq);
-
-		i = (i * 7) % N;
-	} while (i != 1);
-
-	while (!merged_iter_pqueue_is_empty(pq)) {
-		struct pq_entry e = merged_iter_pqueue_remove(&pq);
-		merged_iter_pqueue_check(pq);
-
-		EXPECT(reftable_record_type(e.rec) == BLOCK_TYPE_REF);
-		if (last)
-			EXPECT(strcmp(last, e.rec->u.ref.refname) < 0);
-		last = e.rec->u.ref.refname;
-	}
-
-	for (i = 0; i < N; i++)
-		reftable_record_release(&recs[i]);
-	merged_iter_pqueue_release(&pq);
-}
-
-int pq_test_main(int argc, const char *argv[])
-{
-	RUN_TEST(test_pq);
-	return 0;
-}
diff --git a/reftable/reftable-tests.h b/reftable/reftable-tests.h
index d5e03dcc1b..3bc1d88d9b 100644
--- a/reftable/reftable-tests.h
+++ b/reftable/reftable-tests.h
@@ -11,7 +11,6 @@ https://developers.google.com/open-source/licenses/bsd
 
 int basics_test_main(int argc, const char **argv);
 int block_test_main(int argc, const char **argv);
-int pq_test_main(int argc, const char **argv);
 int record_test_main(int argc, const char **argv);
 int readwrite_test_main(int argc, const char **argv);
 int stack_test_main(int argc, const char **argv);
diff --git a/t/helper/test-reftable.c b/t/helper/test-reftable.c
index 9d378427da..672eaedae0 100644
--- a/t/helper/test-reftable.c
+++ b/t/helper/test-reftable.c
@@ -7,7 +7,6 @@ int cmd__reftable(int argc, const char **argv)
 	/* test from simple to complex. */
 	block_test_main(argc, argv);
 	tree_test_main(argc, argv);
-	pq_test_main(argc, argv);
 	readwrite_test_main(argc, argv);
 	stack_test_main(argc, argv);
 	return 0;
diff --git a/t/unit-tests/t-reftable-pq.c b/t/unit-tests/t-reftable-pq.c
new file mode 100644
index 0000000000..039bd0f1f9
--- /dev/null
+++ b/t/unit-tests/t-reftable-pq.c
@@ -0,0 +1,152 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "test-lib.h"
+#include "reftable/constants.h"
+#include "reftable/pq.h"
+
+static void merged_iter_pqueue_check(const struct merged_iter_pqueue *pq)
+{
+	for (size_t i = 1; i < pq->len; i++) {
+		size_t parent = (i - 1) / 2;
+		check(pq_less(&pq->heap[parent], &pq->heap[i]));
+	}
+}
+
+static int pq_entry_equal(struct pq_entry *a, struct pq_entry *b)
+{
+	return !reftable_record_cmp(a->rec, b->rec) && (a->index == b->index);
+}
+
+static void t_pq_record(void)
+{
+	struct merged_iter_pqueue pq = { 0 };
+	struct reftable_record recs[54];
+	size_t N = ARRAY_SIZE(recs) - 1, i;
+	char *last = NULL;
+
+	for (i = 0; i < N; i++) {
+		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
+		recs[i].u.ref.refname = xstrfmt("%02"PRIuMAX, (uintmax_t)i);
+	}
+
+	i = 1;
+	do {
+		struct pq_entry e = {
+			.rec = &recs[i],
+		};
+
+		merged_iter_pqueue_add(&pq, &e);
+		merged_iter_pqueue_check(&pq);
+		i = (i * 7) % N;
+	} while (i != 1);
+
+	while (!merged_iter_pqueue_is_empty(pq)) {
+		struct pq_entry top = merged_iter_pqueue_top(pq);
+		struct pq_entry e = merged_iter_pqueue_remove(&pq);
+		merged_iter_pqueue_check(&pq);
+
+		check(pq_entry_equal(&top, &e));
+		check(reftable_record_type(e.rec) == BLOCK_TYPE_REF);
+		if (last)
+			check_int(strcmp(last, e.rec->u.ref.refname), <, 0);
+		last = e.rec->u.ref.refname;
+	}
+
+	for (i = 0; i < N; i++)
+		reftable_record_release(&recs[i]);
+	merged_iter_pqueue_release(&pq);
+}
+
+static void t_pq_index(void)
+{
+	struct merged_iter_pqueue pq = { 0 };
+	struct reftable_record recs[13];
+	char *last = NULL;
+	size_t N = ARRAY_SIZE(recs), i;
+
+	for (i = 0; i < N; i++) {
+		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
+		recs[i].u.ref.refname = (char *) "refs/heads/master";
+	}
+
+	i = 1;
+	do {
+		struct pq_entry e = {
+			.rec = &recs[i],
+			.index = i,
+		};
+
+		merged_iter_pqueue_add(&pq, &e);
+		merged_iter_pqueue_check(&pq);
+		i = (i * 7) % N;
+	} while (i != 1);
+
+	for (i = N - 1; i > 0; i--) {
+		struct pq_entry top = merged_iter_pqueue_top(pq);
+		struct pq_entry e = merged_iter_pqueue_remove(&pq);
+		merged_iter_pqueue_check(&pq);
+
+		check(pq_entry_equal(&top, &e));
+		check(reftable_record_type(e.rec) == BLOCK_TYPE_REF);
+		check_int(e.index, ==, i);
+		if (last)
+			check_str(last, e.rec->u.ref.refname);
+		last = e.rec->u.ref.refname;
+	}
+
+	merged_iter_pqueue_release(&pq);
+}
+
+static void t_merged_iter_pqueue_top(void)
+{
+	struct merged_iter_pqueue pq = { 0 };
+	struct reftable_record recs[13];
+	size_t N = ARRAY_SIZE(recs), i;
+
+	for (i = 0; i < N; i++) {
+		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
+		recs[i].u.ref.refname = (char *) "refs/heads/master";
+	}
+
+	i = 1;
+	do {
+		struct pq_entry e = {
+			.rec = &recs[i],
+			.index = i,
+		};
+
+		merged_iter_pqueue_add(&pq, &e);
+		merged_iter_pqueue_check(&pq);
+		i = (i * 7) % N;
+	} while (i != 1);
+
+	for (i = N - 1; i > 0; i--) {
+		struct pq_entry top = merged_iter_pqueue_top(pq);
+		struct pq_entry e = merged_iter_pqueue_remove(&pq);
+
+		merged_iter_pqueue_check(&pq);
+		check(pq_entry_equal(&top, &e));
+		check(reftable_record_equal(top.rec, &recs[i], GIT_SHA1_RAWSZ));
+		for (size_t j = 0; i < pq.len; j++) {
+			check(pq_less(&top, &pq.heap[j]));
+			check_int(top.index, >, j);
+		}
+	}
+
+	merged_iter_pqueue_release(&pq);
+}
+
+int cmd_main(int argc, const char *argv[])
+{
+	TEST(t_pq_record(), "pq works with record-based comparison");
+	TEST(t_pq_index(), "pq works with index-based comparison");
+	TEST(t_merged_iter_pqueue_top(), "merged_iter_pqueue_top works");
+
+	return test_done();
+}