diff --git a/src/c/package.d b/src/c/package.d
index 759cb91c7..9d9792616 100644
--- a/src/c/package.d
+++ b/src/c/package.d
@@ -179,7 +179,7 @@ ecl_make_package(cl_object name, cl_object nicknames, cl_object use_list)
 	{
 	pthread_mutexattr_t attr;
 	pthread_mutexattr_init(&attr);
-	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK_NP);
+	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
 	pthread_mutex_init(&x->pack.lock, &attr);
 	pthread_mutexattr_destroy(&attr);
 	}
diff --git a/src/c/threads.d b/src/c/threads.d
index 1c967e2d6..6d871c6f1 100644
--- a/src/c/threads.d
+++ b/src/c/threads.d
@@ -55,6 +55,8 @@ static DWORD main_thread;
 static pthread_key_t cl_env_key;
 # endif
 static pthread_t main_thread;
+static pthread_attr_t pthreadattr;
+static pthread_mutexattr_t mutexattr_error, mutexattr_recursive;
 #endif /* _MSC_VER || mingw32 */
 
 extern void ecl_init_env(struct cl_env_struct *env);
@@ -335,7 +337,7 @@ mp_process_enable(cl_object process)
 	if (mp_process_active_p(process) != Cnil)
 		FEerror("Cannot enable the running process ~A.", 1, process);
         process->process.parent = mp_current_process();
-	code = pthread_create(&process->process.thread, NULL, thread_entry_point, process);
+	code = pthread_create(&process->process.thread, &pthreadattr, thread_entry_point, process);
 	output = (process->process.thread = code)? Cnil : process;
 #endif
 	@(return output)
@@ -426,20 +428,16 @@ mp_process_run_function(cl_narg narg, cl_object name, cl_object function, ...)
 	output->lock.recursive = (recursive != Cnil);
 #else
 	{
-	pthread_mutexattr_t attr;
-	pthread_mutexattr_init(&attr);
 	output->lock.name = name;
 	output->lock.holder = Cnil;
 	output->lock.counter = 0;
 	if (recursive == Cnil) {
-		pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK_NP);
 		output->lock.recursive = 0;
+		pthread_mutex_init(&output->lock.mutex, &mutexattr_error);
 	} else {
-		pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE_NP);
 		output->lock.recursive = 1;
+		pthread_mutex_init(&output->lock.mutex, &mutexattr_recursive);
 	}
-	pthread_mutex_init(&output->lock.mutex, &attr);
-	pthread_mutexattr_destroy(&attr);
 	}
 #endif
 	si_set_finalizer(output, Ct);
@@ -548,13 +546,10 @@ mp_make_condition_variable(void)
 	FEerror("Condition variables are not supported under Windows.", 0);
 	@(return Cnil)
 #else
-	pthread_condattr_t attr;
 	cl_object output;
 
-	pthread_condattr_init(&attr);
 	output = ecl_alloc_object(t_condition_variable);
-	pthread_cond_init(&output->condition_variable.cv, &attr);
-	pthread_condattr_destroy(&attr);
+	pthread_cond_init(&output->condition_variable.cv, NULL);
 	si_set_finalizer(output, Ct);
 	@(return output)
 #endif
@@ -658,11 +653,13 @@ init_threads(cl_env_ptr env)
 #ifdef ECL_WINDOWS_THREADS
 	cl_core.global_lock = CreateMutex(NULL, FALSE, NULL);
 #else
-	pthread_mutexattr_t attr;
-	pthread_mutexattr_init(&attr);
-	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK_NP);
-	pthread_mutex_init(&cl_core.global_lock, &attr);
-	pthread_mutexattr_destroy(&attr);
+	pthread_mutexattr_init(&mutexattr_error);
+	pthread_mutexattr_settype(&mutexattr_error, PTHREAD_MUTEX_ERRORCHECK);
+	pthread_mutexattr_init(&mutexattr_recursive);
+	pthread_mutexattr_settype(&mutexattr_recursive, PTHREAD_MUTEX_RECURSIVE);
+	pthread_attr_init(&pthreadattr);
+	pthread_attr_setdetachstate(&pthreadattr, PTHREAD_CREATE_DETACHED);
+	pthread_mutex_init(&cl_core.global_lock, &mutexattr_error);
 #endif
 	cl_core.processes = OBJNULL;
 
diff --git a/src/h/config.h.in b/src/h/config.h.in
index cfbe42094..60beb5761 100644
--- a/src/h/config.h.in
+++ b/src/h/config.h.in
@@ -403,21 +403,6 @@ typedef unsigned @CL_FIXNUM_TYPE@ cl_hashkey;
 # include "@ECL_FPE_CODE@"
 #endif
 
-#if defined(ECL_THREADS)
-# if defined(darwin) || defined(freebsd) || defined(gnu) || defined(openbsd) || defined(netbsd)
-#  define PTHREAD_MUTEX_ERRORCHECK_NP PTHREAD_MUTEX_ERRORCHECK
-#  define PTHREAD_MUTEX_RECURSIVE_NP PTHREAD_MUTEX_RECURSIVE
-#  define PTHREAD_MUTEX_NORMAL_NP PTHREAD_MUTEX_NORMAL
-# endif
-# if defined(cygwin)
-#  define PTHREAD_MUTEX_FAST_NP PTHREAD_MUTEX_NORMAL
-#  define PTHREAD_MUTEX_RECURSIVE_NP PTHREAD_MUTEX_RECURSIVE
-#  define PTHREAD_MUTEX_ERRORCHECK_NP PTHREAD_MUTEX_ERRORCHECK
-#  define PTHREAD_MUTEX_TIMED_NP PTHREAD_MUTEX_NORMAL
-#  define PTHREAD_MUTEX_ADAPTIVE_NP PTHREAD_MUTEX_NORMAL
-# endif
-#endif
-
 #ifdef ECL_INCLUDE_MATH_H
 # include <math.h>
 # ifdef _MSC_VER
diff --git a/src/h/ecl.h b/src/h/ecl.h
index 2ae6890c2..d3a7c681f 100644
--- a/src/h/ecl.h
+++ b/src/h/ecl.h
@@ -17,6 +17,8 @@
 #ifndef ECL_H
 #define ECL_H
 
+#define _XOPEN_SOURCE 600	/* POSIX and XPG and later revisions */
+
 #include <sys/types.h>		/* size_t, pthread_t, pthread_mutex_t */
 #ifdef __OpenBSD__		/* same, but for OpenBSD (bug in OpenBSD!) */
 # include <pthread.h>