diff --git a/lib/libthr/thread/thr_stack.c b/lib/libthr/thread/thr_stack.c
index cb390cc..500c340 100644
--- a/lib/libthr/thread/thr_stack.c
+++ b/lib/libthr/thread/thr_stack.c
@@ -30,6 +30,8 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <sys/queue.h>
+#include <sys/resource.h>
+#include <sys/sysctl.h>
 #include <stdlib.h>
 #include <pthread.h>
 #include <link.h>
@@ -139,6 +141,26 @@ _thr_stack_fix_protection(struct pthread *thrd)
 	    _rtld_get_stack_prot());
 }
 
+static void
+singlethr_map_stacks_exec(void)
+{
+	int mib[2];
+	struct rlimit rlim;
+	u_long usrstack;
+	size_t len;
+	
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_USRSTACK;
+	len = sizeof(usrstack);
+	if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &usrstack, &len, NULL, 0)
+	    == -1)
+		return;
+	if (getrlimit(RLIMIT_STACK, &rlim) == -1)
+		return;
+	mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur),
+	    rlim.rlim_cur, _rtld_get_stack_prot());
+}
+
 void __pthread_map_stacks_exec(void);
 void
 __pthread_map_stacks_exec(void)
@@ -146,6 +168,10 @@ __pthread_map_stacks_exec(void)
 	struct pthread *curthread, *thrd;
 	struct stack *st;
 
+	if (!_thr_isthreaded()) {
+		singlethr_map_stacks_exec();
+		return;
+	}
 	curthread = _get_curthread();
 	THREAD_LIST_RDLOCK(curthread);
 	LIST_FOREACH(st, &mstackq, qe)