diff --git a/include/jemalloc/internal/ql.h b/include/jemalloc/internal/ql.h
index 16cd88d5..db672194 100644
--- a/include/jemalloc/internal/ql.h
+++ b/include/jemalloc/internal/ql.h
@@ -14,24 +14,25 @@ struct {								\
 #define ql_elm(a_type)	qr(a_type)
 
 /* List functions. */
+#define ql_first(a_head) ((a_head)->qlh_first)
+
 #define ql_new(a_head) do {						\
-	(a_head)->qlh_first = NULL;					\
+	ql_first(a_head) = NULL;					\
 } while (0)
 
+#define ql_clear(a_head) ql_new(a_head)
+
 #define ql_move(a_head_dest, a_head_src) do {				\
-	(a_head_dest)->qlh_first = (a_head_src)->qlh_first;		\
-	(a_head_src)->qlh_first = NULL;					\
+	ql_first(a_head_dest) = ql_first(a_head_src);			\
+	ql_clear(a_head_src);						\
 } while (0)
 
-#define ql_empty(a_head) ((a_head)->qlh_first == NULL)
+#define ql_empty(a_head) (ql_first(a_head) == NULL)
 
 #define ql_elm_new(a_elm, a_field) qr_new((a_elm), a_field)
 
-#define ql_first(a_head) ((a_head)->qlh_first)
-
 #define ql_last(a_head, a_field)					\
-	((ql_first(a_head) != NULL)					\
-	    ? qr_prev(ql_first(a_head), a_field) : NULL)
+	(ql_empty(a_head) ? NULL : qr_prev(ql_first(a_head), a_field))
 
 #define ql_next(a_head, a_elm, a_field)					\
 	((ql_last(a_head, a_field) != (a_elm))				\
@@ -52,27 +53,27 @@ struct {								\
 	qr_after_insert((a_qlelm), (a_elm), a_field)
 
 #define ql_head_insert(a_head, a_elm, a_field) do {			\
-	if (ql_first(a_head) != NULL) {					\
+	if (!ql_empty(a_head)) {					\
 		qr_before_insert(ql_first(a_head), (a_elm), a_field);	\
 	}								\
 	ql_first(a_head) = (a_elm);					\
 } while (0)
 
 #define ql_tail_insert(a_head, a_elm, a_field) do {			\
-	if (ql_first(a_head) != NULL) {					\
+	if (!ql_empty(a_head)) {					\
 		qr_before_insert(ql_first(a_head), (a_elm), a_field);	\
 	}								\
 	ql_first(a_head) = qr_next((a_elm), a_field);			\
 } while (0)
 
 #define ql_concat(a_head_a, a_head_b, a_field) do {			\
-	if (ql_first(a_head_a) == NULL) {				\
-		ql_first(a_head_a) = ql_first(a_head_b);		\
-	} else if (ql_first(a_head_b) != NULL) {			\
+	if (ql_empty(a_head_a)) {					\
+		ql_move(a_head_a, a_head_b);				\
+	} else if (!ql_empty(a_head_b)) {				\
 		qr_meld(ql_first(a_head_a), ql_first(a_head_b),		\
 		    a_field);						\
+		ql_clear(a_head_b);					\
 	}								\
-	ql_first(a_head_b) = NULL;					\
 } while (0)
 
 #define ql_remove(a_head, a_elm, a_field) do {				\
@@ -82,7 +83,7 @@ struct {								\
 	if (ql_first(a_head) != (a_elm)) {				\
 		qr_remove((a_elm), a_field);				\
 	} else {							\
-		ql_first(a_head) = NULL;				\
+		ql_clear(a_head);					\
 	}								\
 } while (0)
 
@@ -98,11 +99,11 @@ struct {								\
 
 #define ql_split(a_head_a, a_elm, a_head_b, a_field) do {		\
 	if (ql_first(a_head_a) == (a_elm)) {				\
-		ql_first(a_head_a) = NULL;				\
+		ql_move(a_head_b, a_head_a);				\
 	} else {							\
 		qr_split(ql_first(a_head_a), (a_elm), a_field);		\
+		ql_first(a_head_b) = (a_elm);				\
 	}								\
-	ql_first(a_head_b) = (a_elm);					\
 } while (0)
 
 /*