diff --git a/src/queue.h b/src/queue.h
index 7a4e0cc..36837c8 100644
--- a/src/queue.h
+++ b/src/queue.h
@@ -21,10 +21,10 @@
 typedef void* QUEUE[2];
 
 /* Private macros. */
-#define QUEUE_NEXT(q) (*(QUEUE**) &((*(q))[0]))
-#define QUEUE_PREV(q) (*(QUEUE**) &((*(q))[1]))
-#define QUEUE_PREV_NEXT(q) (QUEUE_NEXT(QUEUE_PREV(q)))
-#define QUEUE_NEXT_PREV(q) (QUEUE_PREV(QUEUE_NEXT(q)))
+#define _QUEUE_NEXT(q) (*(QUEUE**) &((*(q))[0]))
+#define _QUEUE_PREV(q) (*(QUEUE**) &((*(q))[1]))
+#define _QUEUE_PREV_NEXT(q) (_QUEUE_NEXT(_QUEUE_PREV(q)))
+#define _QUEUE_NEXT_PREV(q) (_QUEUE_PREV(_QUEUE_NEXT(q)))
 
 /* Public macros. */
 #define QUEUE_DATA(ptr, type, field) \
@@ -34,34 +34,34 @@ typedef void* QUEUE[2];
  * iterating over its elements results in undefined behavior.
  */
 #define QUEUE_FOREACH(q, h) \
-  for ((q) = QUEUE_NEXT(h); (q) != (h); (q) = QUEUE_NEXT(q))
+  for ((q) = _QUEUE_NEXT(h); (q) != (h); (q) = _QUEUE_NEXT(q))
 
-#define QUEUE_EMPTY(q) ((const QUEUE*) (q) == (const QUEUE*) QUEUE_NEXT(q))
+#define QUEUE_EMPTY(q) ((const QUEUE*) (q) == (const QUEUE*) _QUEUE_NEXT(q))
 
-#define QUEUE_HEAD(q) (QUEUE_NEXT(q))
+#define QUEUE_HEAD(q) (_QUEUE_NEXT(q))
 
-#define QUEUE_INIT(q)    \
-  do {                   \
-    QUEUE_NEXT(q) = (q); \
-    QUEUE_PREV(q) = (q); \
+#define QUEUE_INIT(q)     \
+  do {                    \
+    _QUEUE_NEXT(q) = (q); \
+    _QUEUE_PREV(q) = (q); \
   } while (0)
 
 #define QUEUE_ADD(h, n)                 \
-  do {                                  \
-    QUEUE_PREV_NEXT(h) = QUEUE_NEXT(n); \
-    QUEUE_NEXT_PREV(n) = QUEUE_PREV(h); \
-    QUEUE_PREV(h) = QUEUE_PREV(n);      \
-    QUEUE_PREV_NEXT(h) = (h);           \
+  do {                                    \
+    _QUEUE_PREV_NEXT(h) = _QUEUE_NEXT(n); \
+    _QUEUE_NEXT_PREV(n) = _QUEUE_PREV(h); \
+    _QUEUE_PREV(h) = _QUEUE_PREV(n);      \
+    _QUEUE_PREV_NEXT(h) = (h);            \
   } while (0)
 
-#define QUEUE_SPLIT(h, q, n)       \
-  do {                             \
-    QUEUE_PREV(n) = QUEUE_PREV(h); \
-    QUEUE_PREV_NEXT(n) = (n);      \
-    QUEUE_NEXT(n) = (q);           \
-    QUEUE_PREV(h) = QUEUE_PREV(q); \
-    QUEUE_PREV_NEXT(h) = (h);      \
-    QUEUE_PREV(q) = (n);           \
+#define QUEUE_SPLIT(h, q, n)         \
+  do {                               \
+    _QUEUE_PREV(n) = _QUEUE_PREV(h); \
+    _QUEUE_PREV_NEXT(n) = (n);       \
+    _QUEUE_NEXT(n) = (q);            \
+    _QUEUE_PREV(h) = _QUEUE_PREV(q); \
+    _QUEUE_PREV_NEXT(h) = (h);       \
+    _QUEUE_PREV(q) = (n);            \
   } while (0)
 
 #define QUEUE_MOVE(h, n)        \
@@ -74,26 +74,26 @@ typedef void* QUEUE[2];
     }                           \
   } while (0)
 
-#define QUEUE_INSERT_HEAD(h, q)    \
-  do {                             \
-    QUEUE_NEXT(q) = QUEUE_NEXT(h); \
-    QUEUE_PREV(q) = (h);           \
-    QUEUE_NEXT_PREV(q) = (q);      \
-    QUEUE_NEXT(h) = (q);           \
+#define QUEUE_INSERT_HEAD(h, q)      \
+  do {                               \
+    _QUEUE_NEXT(q) = _QUEUE_NEXT(h); \
+    _QUEUE_PREV(q) = (h);            \
+    _QUEUE_NEXT_PREV(q) = (q);       \
+    _QUEUE_NEXT(h) = (q);            \
   } while (0)
 
-#define QUEUE_INSERT_TAIL(h, q)    \
-  do {                             \
-    QUEUE_NEXT(q) = (h);           \
-    QUEUE_PREV(q) = QUEUE_PREV(h); \
-    QUEUE_PREV_NEXT(q) = (q);      \
-    QUEUE_PREV(h) = (q);           \
+#define QUEUE_INSERT_TAIL(h, q)      \
+  do {                               \
+    _QUEUE_NEXT(q) = (h);            \
+    _QUEUE_PREV(q) = _QUEUE_PREV(h); \
+    _QUEUE_PREV_NEXT(q) = (q);       \
+    _QUEUE_PREV(h) = (q);            \
   } while (0)
 
-#define QUEUE_REMOVE(q)                 \
-  do {                                  \
-    QUEUE_PREV_NEXT(q) = QUEUE_NEXT(q); \
-    QUEUE_NEXT_PREV(q) = QUEUE_PREV(q); \
+#define QUEUE_REMOVE(q)                   \
+  do {                                    \
+    _QUEUE_PREV_NEXT(q) = _QUEUE_NEXT(q); \
+    _QUEUE_NEXT_PREV(q) = _QUEUE_PREV(q); \
   } while (0)
 
 #endif /* QUEUE_H_ */