diff --git a/configure.ac b/configure.ac
index c1b46dc3..e704d2de 100644
--- a/configure.ac
+++ b/configure.ac
@@ -285,6 +285,21 @@ if test "x${je_cv_attribute}" = "xyes" ; then
     JE_CFLAGS_APPEND([-fvisibility=hidden])
   fi
 fi
+dnl Check for tls_model attribute support (clang 3.0 still lacks support).
+SAVED_CFLAGS="${CFLAGS}"
+JE_CFLAGS_APPEND([-Werror])
+JE_COMPILABLE([tls_model attribute], [],
+              [static __thread int
+               __attribute__((tls_model("initial-exec"))) foo;
+               foo = 0;],
+              [je_cv_tls_model])
+CFLAGS="${SAVED_CFLAGS}"
+if test "x${je_cv_tls_model}" = "xyes" ; then
+  AC_DEFINE([JEMALLOC_TLS_MODEL],
+            [__attribute__((tls_model("initial-exec")))])
+else
+  AC_DEFINE([JEMALLOC_TLS_MODEL], [ ])
+fi
 
 JE_COMPILABLE([mremap(...MREMAP_FIXED...)], [
 #define _GNU_SOURCE
@@ -719,7 +734,7 @@ AC_CACHE_CHECK([STATIC_PAGE_SHIFT],
 	return 1;
     }
     fprintf(f, "%u\n", ffs((int)result) - 1);
-    close(f);
+    fclose(f);
 
     return 0;
 ]])],
diff --git a/include/jemalloc/internal/tsd.h b/include/jemalloc/internal/tsd.h
index 60aaa427..35ae5e3c 100644
--- a/include/jemalloc/internal/tsd.h
+++ b/include/jemalloc/internal/tsd.h
@@ -87,14 +87,14 @@ extern bool		a_name##_booted;
 /* malloc_tsd_data(). */
 #ifdef JEMALLOC_MALLOC_THREAD_CLEANUP
 #define	malloc_tsd_data(a_attr, a_name, a_type, a_initializer)		\
-a_attr __thread a_type JEMALLOC_ATTR(tls_model("initial-exec"))		\
+a_attr __thread a_type JEMALLOC_TLS_MODEL				\
     a_name##_tls = a_initializer;					\
-a_attr __thread bool JEMALLOC_ATTR(tls_model("initial-exec"))		\
+a_attr __thread bool JEMALLOC_TLS_MODEL					\
     a_name##_initialized = false;					\
 a_attr bool		a_name##_booted = false;
 #elif (defined(JEMALLOC_TLS))
 #define	malloc_tsd_data(a_attr, a_name, a_type, a_initializer)		\
-a_attr __thread a_type JEMALLOC_ATTR(tls_model("initial-exec"))		\
+a_attr __thread a_type JEMALLOC_TLS_MODEL				\
     a_name##_tls = a_initializer;					\
 a_attr pthread_key_t	a_name##_tsd;					\
 a_attr bool		a_name##_booted = false;
diff --git a/include/jemalloc/jemalloc_defs.h.in b/include/jemalloc/jemalloc_defs.h.in
index e4bfa04a..040753a6 100644
--- a/include/jemalloc/jemalloc_defs.h.in
+++ b/include/jemalloc/jemalloc_defs.h.in
@@ -108,6 +108,9 @@
 #  define JEMALLOC_ATTR(s) JEMALLOC_CATTR(s,)
 #endif
 
+/* Non-empty if the tls_model attribute is supported. */
+#undef JEMALLOC_TLS_MODEL
+
 /* JEMALLOC_CC_SILENCE enables code that silences unuseful compiler warnings. */
 #undef JEMALLOC_CC_SILENCE