diff --git a/negotiator/skipping.c b/negotiator/skipping.c
index abedb70a48..616df6bf3a 100644
--- a/negotiator/skipping.c
+++ b/negotiator/skipping.c
@@ -134,7 +134,6 @@ static int push_parent(struct data *data, struct entry *entry,
 	struct entry *parent_entry;
 
 	if (to_push->object.flags & SEEN) {
-		int i;
 		if (to_push->object.flags & POPPED)
 			/*
 			 * The entry for this commit has already been popped,
@@ -145,7 +144,7 @@ static int push_parent(struct data *data, struct entry *entry,
 		/*
 		 * Find the existing entry and use it.
 		 */
-		for (i = 0; i < data->rev_list.nr; i++) {
+		for (size_t i = 0; i < data->rev_list.nr; i++) {
 			parent_entry = data->rev_list.array[i].data;
 			if (parent_entry->commit == to_push)
 				goto parent_found;
@@ -248,7 +247,7 @@ static int ack(struct fetch_negotiator *n, struct commit *c)
 static void release(struct fetch_negotiator *n)
 {
 	struct data *data = n->data;
-	for (int i = 0; i < data->rev_list.nr; i++)
+	for (size_t i = 0; i < data->rev_list.nr; i++)
 		free(data->rev_list.array[i].data);
 	clear_prio_queue(&data->rev_list);
 	FREE_AND_NULL(data);
diff --git a/prio-queue.c b/prio-queue.c
index 450775a374..ec33ac27db 100644
--- a/prio-queue.c
+++ b/prio-queue.c
@@ -1,26 +1,29 @@
 #include "git-compat-util.h"
 #include "prio-queue.h"
 
-static inline int compare(struct prio_queue *queue, int i, int j)
+static inline int compare(struct prio_queue *queue, size_t i, size_t j)
 {
 	int cmp = queue->compare(queue->array[i].data, queue->array[j].data,
 				 queue->cb_data);
 	if (!cmp)
-		cmp = queue->array[i].ctr - queue->array[j].ctr;
+		cmp = (queue->array[i].ctr > queue->array[j].ctr) -
+		      (queue->array[i].ctr < queue->array[j].ctr);
 	return cmp;
 }
 
-static inline void swap(struct prio_queue *queue, int i, int j)
+static inline void swap(struct prio_queue *queue, size_t i, size_t j)
 {
 	SWAP(queue->array[i], queue->array[j]);
 }
 
 void prio_queue_reverse(struct prio_queue *queue)
 {
-	int i, j;
+	size_t i, j;
 
 	if (queue->compare)
 		BUG("prio_queue_reverse() on non-LIFO queue");
+	if (!queue->nr)
+		return;
 	for (i = 0; i < (j = (queue->nr - 1) - i); i++)
 		swap(queue, i, j);
 }
@@ -35,7 +38,7 @@ void clear_prio_queue(struct prio_queue *queue)
 
 void prio_queue_put(struct prio_queue *queue, void *thing)
 {
-	int ix, parent;
+	size_t ix, parent;
 
 	/* Append at the end */
 	ALLOC_GROW(queue->array, queue->nr + 1, queue->alloc);
@@ -58,7 +61,7 @@ void prio_queue_put(struct prio_queue *queue, void *thing)
 void *prio_queue_get(struct prio_queue *queue)
 {
 	void *result;
-	int ix, child;
+	size_t ix, child;
 
 	if (!queue->nr)
 		return NULL;
diff --git a/prio-queue.h b/prio-queue.h
index 4f9a37e6be..36f370625f 100644
--- a/prio-queue.h
+++ b/prio-queue.h
@@ -30,7 +30,7 @@ struct prio_queue {
 	prio_queue_compare_fn compare;
 	unsigned insertion_ctr;
 	void *cb_data;
-	int alloc, nr;
+	size_t alloc, nr;
 	struct prio_queue_entry *array;
 };