diff --git a/include/jemalloc/internal/arena.h b/include/jemalloc/internal/arena.h
index 12c61797..9e2375ce 100644
--- a/include/jemalloc/internal/arena.h
+++ b/include/jemalloc/internal/arena.h
@@ -512,7 +512,7 @@ arena_chunk_map_bits_t	*arena_bitselm_get(arena_chunk_t *chunk,
     size_t pageind);
 arena_chunk_map_misc_t	*arena_miscelm_get(arena_chunk_t *chunk,
     size_t pageind);
-size_t	arena_miscelm_to_pageind(arena_chunk_map_misc_t *miscelm);
+size_t	arena_miscelm_to_pageind(const arena_chunk_map_misc_t *miscelm);
 void	*arena_miscelm_to_rpages(arena_chunk_map_misc_t *miscelm);
 arena_chunk_map_misc_t	*arena_rd_to_miscelm(arena_runs_dirty_link_t *rd);
 arena_chunk_map_misc_t	*arena_run_to_miscelm(arena_run_t *run);
@@ -590,7 +590,7 @@ arena_miscelm_get(arena_chunk_t *chunk, size_t pageind)
 }
 
 JEMALLOC_ALWAYS_INLINE size_t
-arena_miscelm_to_pageind(arena_chunk_map_misc_t *miscelm)
+arena_miscelm_to_pageind(const arena_chunk_map_misc_t *miscelm)
 {
 	arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(miscelm);
 	size_t pageind = ((uintptr_t)miscelm - ((uintptr_t)chunk +
diff --git a/include/jemalloc/internal/rb.h b/include/jemalloc/internal/rb.h
index b460d74b..7ddc383b 100644
--- a/include/jemalloc/internal/rb.h
+++ b/include/jemalloc/internal/rb.h
@@ -178,11 +178,11 @@ a_prefix##next(a_rbt_type *rbtree, a_type *node);			\
 a_attr a_type *								\
 a_prefix##prev(a_rbt_type *rbtree, a_type *node);			\
 a_attr a_type *								\
-a_prefix##search(a_rbt_type *rbtree, a_type *key);			\
+a_prefix##search(a_rbt_type *rbtree, const a_type *key);		\
 a_attr a_type *								\
-a_prefix##nsearch(a_rbt_type *rbtree, a_type *key);			\
+a_prefix##nsearch(a_rbt_type *rbtree, const a_type *key);		\
 a_attr a_type *								\
-a_prefix##psearch(a_rbt_type *rbtree, a_type *key);			\
+a_prefix##psearch(a_rbt_type *rbtree, const a_type *key);		\
 a_attr void								\
 a_prefix##insert(a_rbt_type *rbtree, a_type *node);			\
 a_attr void								\
@@ -263,7 +263,7 @@ a_prefix##reverse_iter(a_rbt_type *rbtree, a_type *start,		\
  *            last/first.
  *
  *   static ex_node_t *
- *   ex_search(ex_t *tree, ex_node_t *key);
+ *   ex_search(ex_t *tree, const ex_node_t *key);
  *       Description: Search for node that matches key.
  *       Args:
  *         tree: Pointer to an initialized red-black tree object.
@@ -271,9 +271,9 @@ a_prefix##reverse_iter(a_rbt_type *rbtree, a_type *start,		\
  *       Ret: Node in tree that matches key, or NULL if no match.
  *
  *   static ex_node_t *
- *   ex_nsearch(ex_t *tree, ex_node_t *key);
+ *   ex_nsearch(ex_t *tree, const ex_node_t *key);
  *   static ex_node_t *
- *   ex_psearch(ex_t *tree, ex_node_t *key);
+ *   ex_psearch(ex_t *tree, const ex_node_t *key);
  *       Description: Search for node that matches key.  If no match is found,
  *                    return what would be key's successor/predecessor, were
  *                    key in tree.
@@ -406,7 +406,7 @@ a_prefix##prev(a_rbt_type *rbtree, a_type *node) {			\
     return (ret);							\
 }									\
 a_attr a_type *								\
-a_prefix##search(a_rbt_type *rbtree, a_type *key) {			\
+a_prefix##search(a_rbt_type *rbtree, const a_type *key) {		\
     a_type *ret;							\
     int cmp;								\
     ret = rbtree->rbt_root;						\
@@ -424,7 +424,7 @@ a_prefix##search(a_rbt_type *rbtree, a_type *key) {			\
     return (ret);							\
 }									\
 a_attr a_type *								\
-a_prefix##nsearch(a_rbt_type *rbtree, a_type *key) {			\
+a_prefix##nsearch(a_rbt_type *rbtree, const a_type *key) {		\
     a_type *ret;							\
     a_type *tnode = rbtree->rbt_root;					\
     ret = &rbtree->rbt_nil;						\
@@ -446,7 +446,7 @@ a_prefix##nsearch(a_rbt_type *rbtree, a_type *key) {			\
     return (ret);							\
 }									\
 a_attr a_type *								\
-a_prefix##psearch(a_rbt_type *rbtree, a_type *key) {			\
+a_prefix##psearch(a_rbt_type *rbtree, const a_type *key) {		\
     a_type *ret;							\
     a_type *tnode = rbtree->rbt_root;					\
     ret = &rbtree->rbt_nil;						\
diff --git a/src/arena.c b/src/arena.c
index 58797ded..844d721c 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -62,7 +62,7 @@ arena_miscelm_key_size_get(const arena_chunk_map_misc_t *miscelm)
 }
 
 JEMALLOC_INLINE_C size_t
-arena_miscelm_size_get(arena_chunk_map_misc_t *miscelm)
+arena_miscelm_size_get(const arena_chunk_map_misc_t *miscelm)
 {
 	arena_chunk_t *chunk;
 	size_t pageind, mapbits;
@@ -76,7 +76,7 @@ arena_miscelm_size_get(arena_chunk_map_misc_t *miscelm)
 }
 
 JEMALLOC_INLINE_C int
-arena_run_comp(arena_chunk_map_misc_t *a, arena_chunk_map_misc_t *b)
+arena_run_comp(const arena_chunk_map_misc_t *a, const arena_chunk_map_misc_t *b)
 {
 	uintptr_t a_miscelm = (uintptr_t)a;
 	uintptr_t b_miscelm = (uintptr_t)b;
@@ -169,7 +169,8 @@ run_quantize_first(size_t size)
 }
 
 JEMALLOC_INLINE_C int
-arena_avail_comp(arena_chunk_map_misc_t *a, arena_chunk_map_misc_t *b)
+arena_avail_comp(const arena_chunk_map_misc_t *a,
+    const arena_chunk_map_misc_t *b)
 {
 	int ret;
 	uintptr_t a_miscelm = (uintptr_t)a;
diff --git a/src/extent.c b/src/extent.c
index 13f94411..9f5146e5 100644
--- a/src/extent.c
+++ b/src/extent.c
@@ -15,7 +15,7 @@ extent_quantize(size_t size)
 }
 
 JEMALLOC_INLINE_C int
-extent_szad_comp(extent_node_t *a, extent_node_t *b)
+extent_szad_comp(const extent_node_t *a, const extent_node_t *b)
 {
 	int ret;
 	size_t a_qsize = extent_quantize(extent_node_size_get(a));
@@ -41,7 +41,7 @@ rb_gen(, extent_tree_szad_, extent_tree_t, extent_node_t, szad_link,
     extent_szad_comp)
 
 JEMALLOC_INLINE_C int
-extent_ad_comp(extent_node_t *a, extent_node_t *b)
+extent_ad_comp(const extent_node_t *a, const extent_node_t *b)
 {
 	uintptr_t a_addr = (uintptr_t)extent_node_addr_get(a);
 	uintptr_t b_addr = (uintptr_t)extent_node_addr_get(b);
diff --git a/test/unit/rb.c b/test/unit/rb.c
index b38eb0e3..0262037b 100644
--- a/test/unit/rb.c
+++ b/test/unit/rb.c
@@ -21,7 +21,7 @@ struct node_s {
 };
 
 static int
-node_cmp(node_t *a, node_t *b) {
+node_cmp(const node_t *a, const node_t *b) {
 	int ret;
 
 	assert_u32_eq(a->magic, NODE_MAGIC, "Bad magic");