diff --git a/builtin/name-rev.c b/builtin/name-rev.c
index 27138fdce47..b221d300147 100644
--- a/builtin/name-rev.c
+++ b/builtin/name-rev.c
@@ -390,9 +390,9 @@ static void name_tips(void)
 	}
 }
 
-static const struct object_id *nth_tip_table_ent(size_t ix, void *table_)
+static const struct object_id *nth_tip_table_ent(size_t ix, const void *table_)
 {
-	struct tip_table_entry *table = table_;
+	const struct tip_table_entry *table = table_;
 	return &table[ix].oid;
 }
 
diff --git a/commit-graph.c b/commit-graph.c
index 248f1efb73e..b09fce5f573 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -1012,9 +1012,9 @@ static int write_graph_chunk_oids(struct hashfile *f,
 	return 0;
 }
 
-static const struct object_id *commit_to_oid(size_t index, void *table)
+static const struct object_id *commit_to_oid(size_t index, const void *table)
 {
-	struct commit **commits = table;
+	const struct commit * const *commits = table;
 	return &commits[index]->object.oid;
 }
 
diff --git a/commit.c b/commit.c
index 39eab5b36bc..fd2831dad32 100644
--- a/commit.c
+++ b/commit.c
@@ -105,9 +105,9 @@ static timestamp_t parse_commit_date(const char *buf, const char *tail)
 	return parse_timestamp(dateptr, NULL, 10);
 }
 
-static const struct object_id *commit_graft_oid_access(size_t index, void *table)
+static const struct object_id *commit_graft_oid_access(size_t index, const void *table)
 {
-	struct commit_graft **commit_graft_table = table;
+	const struct commit_graft * const *commit_graft_table = table;
 	return &commit_graft_table[index]->oid;
 }
 
diff --git a/hash-lookup.c b/hash-lookup.c
index d15bb345749..b98ed5e11e8 100644
--- a/hash-lookup.c
+++ b/hash-lookup.c
@@ -50,7 +50,7 @@ static uint32_t take2(const struct object_id *oid, size_t ofs)
  * The oid of element i (between 0 and nr - 1) should be returned
  * by "fn(i, table)".
  */
-int oid_pos(const struct object_id *oid, void *table, size_t nr,
+int oid_pos(const struct object_id *oid, const void *table, size_t nr,
 	    oid_access_fn fn)
 {
 	size_t hi = nr;
diff --git a/hash-lookup.h b/hash-lookup.h
index 7b3ecad1f03..dbd71ebaf73 100644
--- a/hash-lookup.h
+++ b/hash-lookup.h
@@ -1,10 +1,10 @@
 #ifndef HASH_LOOKUP_H
 #define HASH_LOOKUP_H
 
-typedef const struct object_id *oid_access_fn(size_t index, void *table);
+typedef const struct object_id *oid_access_fn(size_t index, const void *table);
 
 int oid_pos(const struct object_id *oid,
-	    void *table,
+	    const void *table,
 	    size_t nr,
 	    oid_access_fn fn);
 
diff --git a/oid-array.c b/oid-array.c
index a19235afbf8..73ba76e9e9a 100644
--- a/oid-array.c
+++ b/oid-array.c
@@ -22,9 +22,9 @@ void oid_array_sort(struct oid_array *array)
 	array->sorted = 1;
 }
 
-static const struct object_id *oid_access(size_t index, void *table)
+static const struct object_id *oid_access(size_t index, const void *table)
 {
-	struct object_id *array = table;
+	const struct object_id *array = table;
 	return &array[index];
 }
 
diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index f21259dfc82..88d9e696a54 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -610,9 +610,9 @@ static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
 		die("Failed to write bitmap index");
 }
 
-static const struct object_id *oid_access(size_t pos, void *table)
+static const struct object_id *oid_access(size_t pos, const void *table)
 {
-	struct pack_idx_entry **index = table;
+	const struct pack_idx_entry * const *index = table;
 	return &index[pos]->oid;
 }