diff --git a/configure.ac b/configure.ac
index 5cfe9af3..072808cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1845,7 +1845,7 @@ fi
 dnl ============================================================================
 dnl Check for atomic(3) operations as provided on Darwin.
 dnl We need this not for the atomic operations (which are provided above), but
-dnl rather for the OSSpinLock type it exposes.
+dnl rather for the OS_unfair_lock type it exposes.
 
 JE_COMPILABLE([Darwin OSAtomic*()], [
 #include <libkern/OSAtomic.h>
@@ -2011,21 +2011,6 @@ if test "x${je_cv_os_unfair_lock}" = "xyes" ; then
   AC_DEFINE([JEMALLOC_OS_UNFAIR_LOCK], [ ])
 fi
 
-dnl ============================================================================
-dnl Check for spinlock(3) operations as provided on Darwin.
-
-JE_COMPILABLE([Darwin OSSpin*()], [
-#include <libkern/OSAtomic.h>
-#include <inttypes.h>
-], [
-	OSSpinLock lock = 0;
-	OSSpinLockLock(&lock);
-	OSSpinLockUnlock(&lock);
-], [je_cv_osspin])
-if test "x${je_cv_osspin}" = "xyes" ; then
-  AC_DEFINE([JEMALLOC_OSSPIN], [ ])
-fi
-
 dnl ============================================================================
 dnl Darwin-related configuration.
 
@@ -2079,8 +2064,7 @@ dnl ============================================================================
 dnl Enable background threads if possible.
 
 if test "x${have_pthread}" = "x1" -a "x${have_dlsym}" = "x1" \
-    -a "x${je_cv_os_unfair_lock}" != "xyes" \
-    -a "x${je_cv_osspin}" != "xyes" ; then
+    -a "x${je_cv_os_unfair_lock}" != "xyes" ; then
   AC_DEFINE([JEMALLOC_BACKGROUND_THREAD])
 fi
 
diff --git a/include/jemalloc/internal/jemalloc_internal_defs.h.in b/include/jemalloc/internal/jemalloc_internal_defs.h.in
index 3eac2754..3e94c023 100644
--- a/include/jemalloc/internal/jemalloc_internal_defs.h.in
+++ b/include/jemalloc/internal/jemalloc_internal_defs.h.in
@@ -78,12 +78,6 @@
  */
 #undef JEMALLOC_OS_UNFAIR_LOCK
 
-/*
- * Defined if OSSpin*() functions are available, as provided by Darwin, and
- * documented in the spinlock(3) manual page.
- */
-#undef JEMALLOC_OSSPIN
-
 /* Defined if syscall(2) is usable. */
 #undef JEMALLOC_USE_SYSCALL
 
diff --git a/include/jemalloc/internal/jemalloc_preamble.h.in b/include/jemalloc/internal/jemalloc_preamble.h.in
index 1b12aeec..857fa326 100644
--- a/include/jemalloc/internal/jemalloc_preamble.h.in
+++ b/include/jemalloc/internal/jemalloc_preamble.h.in
@@ -21,7 +21,7 @@
 #  include "../jemalloc@install_suffix@.h"
 #endif
 
-#if (defined(JEMALLOC_OSATOMIC) || defined(JEMALLOC_OSSPIN))
+#if defined(JEMALLOC_OSATOMIC)
 #include <libkern/OSAtomic.h>
 #endif
 
diff --git a/include/jemalloc/internal/mutex.h b/include/jemalloc/internal/mutex.h
index 5a955d9e..c530cc9d 100644
--- a/include/jemalloc/internal/mutex.h
+++ b/include/jemalloc/internal/mutex.h
@@ -37,8 +37,6 @@ struct malloc_mutex_s {
 #  endif
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
 			os_unfair_lock		lock;
-#elif (defined(JEMALLOC_OSSPIN))
-			OSSpinLock		lock;
 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
 			pthread_mutex_t		lock;
 			malloc_mutex_t		*postponed_next;
@@ -84,10 +82,6 @@ struct malloc_mutex_s {
 #    define MALLOC_MUTEX_LOCK(m)    os_unfair_lock_lock(&(m)->lock)
 #    define MALLOC_MUTEX_UNLOCK(m)  os_unfair_lock_unlock(&(m)->lock)
 #    define MALLOC_MUTEX_TRYLOCK(m) (!os_unfair_lock_trylock(&(m)->lock))
-#elif (defined(JEMALLOC_OSSPIN))
-#    define MALLOC_MUTEX_LOCK(m)    OSSpinLockLock(&(m)->lock)
-#    define MALLOC_MUTEX_UNLOCK(m)  OSSpinLockUnlock(&(m)->lock)
-#    define MALLOC_MUTEX_TRYLOCK(m) (!OSSpinLockTry(&(m)->lock))
 #else
 #    define MALLOC_MUTEX_LOCK(m)    pthread_mutex_lock(&(m)->lock)
 #    define MALLOC_MUTEX_UNLOCK(m)  pthread_mutex_unlock(&(m)->lock)
@@ -110,10 +104,6 @@ struct malloc_mutex_s {
   {{{LOCK_PROF_DATA_INITIALIZER, OS_UNFAIR_LOCK_INIT}},		\
       WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT)}
 #  endif
-#elif (defined(JEMALLOC_OSSPIN))
-#  define MALLOC_MUTEX_INITIALIZER					\
-     {{{LOCK_PROF_DATA_INITIALIZER, 0}},				\
-      WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT)}
 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
 #  if (defined(JEMALLOC_DEBUG))
 #     define MALLOC_MUTEX_INITIALIZER					\
diff --git a/src/mutex.c b/src/mutex.c
index 55e37ad4..eb6c4c6d 100644
--- a/src/mutex.c
+++ b/src/mutex.c
@@ -144,9 +144,7 @@ malloc_mutex_init(malloc_mutex_t *mutex, const char *name,
 	}
 #  endif
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
-	mutex->lock = OS_UNFAIR_LOCK_INIT;
-#elif (defined(JEMALLOC_OSSPIN))
-	mutex->lock = 0;
+       mutex->lock = OS_UNFAIR_LOCK_INIT;
 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
 	if (postpone_init) {
 		mutex->postponed_next = postponed_mutexes;
diff --git a/test/include/test/jemalloc_test.h.in b/test/include/test/jemalloc_test.h.in
index 0209aead..c46af5d9 100644
--- a/test/include/test/jemalloc_test.h.in
+++ b/test/include/test/jemalloc_test.h.in
@@ -25,7 +25,7 @@ extern "C" {
 
 #include "test/jemalloc_test_defs.h"
 
-#ifdef JEMALLOC_OSSPIN
+#if defined(JEMALLOC_OSATOMIC)
 #  include <libkern/OSAtomic.h>
 #endif
 
diff --git a/test/include/test/mtx.h b/test/include/test/mtx.h
index 58afbc3d..066a2137 100644
--- a/test/include/test/mtx.h
+++ b/test/include/test/mtx.h
@@ -10,8 +10,6 @@ typedef struct {
 	CRITICAL_SECTION	lock;
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
 	os_unfair_lock		lock;
-#elif (defined(JEMALLOC_OSSPIN))
-	OSSpinLock		lock;
 #else
 	pthread_mutex_t		lock;
 #endif
diff --git a/test/src/mtx.c b/test/src/mtx.c
index a393c01f..d9ce375c 100644
--- a/test/src/mtx.c
+++ b/test/src/mtx.c
@@ -13,8 +13,6 @@ mtx_init(mtx_t *mtx) {
 	}
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
 	mtx->lock = OS_UNFAIR_LOCK_INIT;
-#elif (defined(JEMALLOC_OSSPIN))
-	mtx->lock = 0;
 #else
 	pthread_mutexattr_t attr;
 
@@ -35,7 +33,6 @@ void
 mtx_fini(mtx_t *mtx) {
 #ifdef _WIN32
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
-#elif (defined(JEMALLOC_OSSPIN))
 #else
 	pthread_mutex_destroy(&mtx->lock);
 #endif
@@ -47,8 +44,6 @@ mtx_lock(mtx_t *mtx) {
 	EnterCriticalSection(&mtx->lock);
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
 	os_unfair_lock_lock(&mtx->lock);
-#elif (defined(JEMALLOC_OSSPIN))
-	OSSpinLockLock(&mtx->lock);
 #else
 	pthread_mutex_lock(&mtx->lock);
 #endif
@@ -60,8 +55,6 @@ mtx_unlock(mtx_t *mtx) {
 	LeaveCriticalSection(&mtx->lock);
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
 	os_unfair_lock_unlock(&mtx->lock);
-#elif (defined(JEMALLOC_OSSPIN))
-	OSSpinLockUnlock(&mtx->lock);
 #else
 	pthread_mutex_unlock(&mtx->lock);
 #endif