diff --git a/lib/libc_r/uthread/uthread_info.c b/lib/libc_r/uthread/uthread_info.c
index 06b556e69b18..d091ec12113c 100644
--- a/lib/libc_r/uthread/uthread_info.c
+++ b/lib/libc_r/uthread/uthread_info.c
@@ -304,8 +304,12 @@ void
 pthread_set_name_np(pthread_t thread, char *name)
 {
 	/* Check if the caller has specified a valid thread: */
-	if (thread != NULL && thread->magic == PTHREAD_MAGIC)
+	if (thread != NULL && thread->magic == PTHREAD_MAGIC) {
+		if (thread->name != NULL) {
+			/* Free space for previous name. */
+			free(thread->name);
+		}
 		thread->name = strdup(name);
-	return;
+	}
 }
 #endif
diff --git a/lib/libkse/thread/thr_info.c b/lib/libkse/thread/thr_info.c
index 06b556e69b18..d091ec12113c 100644
--- a/lib/libkse/thread/thr_info.c
+++ b/lib/libkse/thread/thr_info.c
@@ -304,8 +304,12 @@ void
 pthread_set_name_np(pthread_t thread, char *name)
 {
 	/* Check if the caller has specified a valid thread: */
-	if (thread != NULL && thread->magic == PTHREAD_MAGIC)
+	if (thread != NULL && thread->magic == PTHREAD_MAGIC) {
+		if (thread->name != NULL) {
+			/* Free space for previous name. */
+			free(thread->name);
+		}
 		thread->name = strdup(name);
-	return;
+	}
 }
 #endif
diff --git a/lib/libpthread/thread/thr_info.c b/lib/libpthread/thread/thr_info.c
index 06b556e69b18..d091ec12113c 100644
--- a/lib/libpthread/thread/thr_info.c
+++ b/lib/libpthread/thread/thr_info.c
@@ -304,8 +304,12 @@ void
 pthread_set_name_np(pthread_t thread, char *name)
 {
 	/* Check if the caller has specified a valid thread: */
-	if (thread != NULL && thread->magic == PTHREAD_MAGIC)
+	if (thread != NULL && thread->magic == PTHREAD_MAGIC) {
+		if (thread->name != NULL) {
+			/* Free space for previous name. */
+			free(thread->name);
+		}
 		thread->name = strdup(name);
-	return;
+	}
 }
 #endif