diff --git a/src/libgit2/merge.c b/src/libgit2/merge.c
index 8f3fc4602..17cbc1611 100644
--- a/src/libgit2/merge.c
+++ b/src/libgit2/merge.c
@@ -32,7 +32,6 @@
 #include "commit.h"
 #include "oidarray.h"
 #include "merge_driver.h"
-#include "oidmap.h"
 #include "array.h"
 
 #include "git2/types.h"
@@ -1144,24 +1143,28 @@ typedef struct {
 	size_t first_entry;
 } deletes_by_oid_queue;
 
-static void deletes_by_oid_free(git_oidmap *map) {
+GIT_HASHMAP_SETUP(git_merge_deletes_oidmap, const git_oid *, deletes_by_oid_queue *, git_oid_hash32, git_oid_equal);
+
+static void deletes_by_oid_dispose(git_merge_deletes_oidmap *map)
+{
+	git_hashmap_iter_t iter = GIT_HASHMAP_ITER_INIT;
 	deletes_by_oid_queue *queue;
 
 	if (!map)
 		return;
 
-	git_oidmap_foreach_value(map, queue, {
+	while (git_merge_deletes_oidmap_iterate(&iter, NULL, &queue, map) == 0)
 		git_array_clear(queue->arr);
-	});
-	git_oidmap_free(map);
+
+	git_merge_deletes_oidmap_dispose(map);
 }
 
-static int deletes_by_oid_enqueue(git_oidmap *map, git_pool *pool, const git_oid *id, size_t idx)
+static int deletes_by_oid_enqueue(git_merge_deletes_oidmap *map, git_pool *pool, const git_oid *id, size_t idx)
 {
 	deletes_by_oid_queue *queue;
 	size_t *array_entry;
 
-	if ((queue = git_oidmap_get(map, id)) == NULL) {
+	if (git_merge_deletes_oidmap_get(&queue, map, id) != 0) {
 		queue = git_pool_malloc(pool, sizeof(deletes_by_oid_queue));
 		GIT_ERROR_CHECK_ALLOC(queue);
 
@@ -1169,7 +1172,7 @@ static int deletes_by_oid_enqueue(git_oidmap *map, git_pool *pool, const git_oid
 		queue->next_pos = 0;
 		queue->first_entry = idx;
 
-		if (git_oidmap_set(map, id, queue) < 0)
+		if (git_merge_deletes_oidmap_put(map, id, queue) < 0)
 			return -1;
 	} else {
 		array_entry = git_array_alloc(queue->arr);
@@ -1180,13 +1183,14 @@ static int deletes_by_oid_enqueue(git_oidmap *map, git_pool *pool, const git_oid
 	return 0;
 }
 
-static int deletes_by_oid_dequeue(size_t *idx, git_oidmap *map, const git_oid *id)
+static int deletes_by_oid_dequeue(size_t *idx, git_merge_deletes_oidmap *map, const git_oid *id)
 {
 	deletes_by_oid_queue *queue;
 	size_t *array_entry;
+	int error;
 
-	if ((queue = git_oidmap_get(map, id)) == NULL)
-		return GIT_ENOTFOUND;
+	if ((error = git_merge_deletes_oidmap_get(&queue, map, id)) != 0)
+		return error;
 
 	if (queue->next_pos == 0) {
 		*idx = queue->first_entry;
@@ -1209,15 +1213,10 @@ static int merge_diff_mark_similarity_exact(
 {
 	size_t i, j;
 	git_merge_diff *conflict_src, *conflict_tgt;
-	git_oidmap *ours_deletes_by_oid = NULL, *theirs_deletes_by_oid = NULL;
+	git_merge_deletes_oidmap ours_deletes_by_oid = GIT_HASHMAP_INIT,
+	                         theirs_deletes_by_oid = GIT_HASHMAP_INIT;
 	int error = 0;
 
-	if (git_oidmap_new(&ours_deletes_by_oid) < 0 ||
-	    git_oidmap_new(&theirs_deletes_by_oid) < 0) {
-		error = -1;
-		goto done;
-	}
-
 	/* Build a map of object ids to conflicts */
 	git_vector_foreach(&diff_list->conflicts, i, conflict_src) {
 		/* Items can be the source of a rename iff they have an item in the
@@ -1233,13 +1232,13 @@ static int merge_diff_mark_similarity_exact(
 			continue;
 
 		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->our_entry)) {
-			error = deletes_by_oid_enqueue(ours_deletes_by_oid, &diff_list->pool, &conflict_src->ancestor_entry.id, i);
+			error = deletes_by_oid_enqueue(&ours_deletes_by_oid, &diff_list->pool, &conflict_src->ancestor_entry.id, i);
 			if (error < 0)
 				goto done;
 		}
 
 		if (!GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_src->their_entry)) {
-			error = deletes_by_oid_enqueue(theirs_deletes_by_oid, &diff_list->pool, &conflict_src->ancestor_entry.id, i);
+			error = deletes_by_oid_enqueue(&theirs_deletes_by_oid, &diff_list->pool, &conflict_src->ancestor_entry.id, i);
 			if (error < 0)
 				goto done;
 		}
@@ -1250,7 +1249,7 @@ static int merge_diff_mark_similarity_exact(
 			continue;
 
 		if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->our_entry)) {
-			if (deletes_by_oid_dequeue(&i, ours_deletes_by_oid, &conflict_tgt->our_entry.id) == 0) {
+			if (deletes_by_oid_dequeue(&i, &ours_deletes_by_oid, &conflict_tgt->our_entry.id) == 0) {
 				similarity_ours[i].similarity = 100;
 				similarity_ours[i].other_idx = j;
 
@@ -1260,7 +1259,7 @@ static int merge_diff_mark_similarity_exact(
 		}
 
 		if (GIT_MERGE_INDEX_ENTRY_EXISTS(conflict_tgt->their_entry)) {
-			if (deletes_by_oid_dequeue(&i, theirs_deletes_by_oid, &conflict_tgt->their_entry.id) == 0) {
+			if (deletes_by_oid_dequeue(&i, &theirs_deletes_by_oid, &conflict_tgt->their_entry.id) == 0) {
 				similarity_theirs[i].similarity = 100;
 				similarity_theirs[i].other_idx = j;
 
@@ -1271,8 +1270,8 @@ static int merge_diff_mark_similarity_exact(
 	}
 
 done:
-	deletes_by_oid_free(ours_deletes_by_oid);
-	deletes_by_oid_free(theirs_deletes_by_oid);
+	deletes_by_oid_dispose(&ours_deletes_by_oid);
+	deletes_by_oid_dispose(&theirs_deletes_by_oid);
 
 	return error;
 }