diff --git a/src/lib/u/lock.c b/src/lib/u/lock.c
index 025eea4..a2b5b14 100644
--- a/src/lib/u/lock.c
+++ b/src/lib/u/lock.c
@@ -50,7 +50,7 @@
 extern int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
 #endif
 
-#if defined (__SVR4) && defined (__sun)
+#if defined (__SVR4) && defined (__sun) || defined(__linux__)
 #define PTHREAD_MUTEX_RECURSIVE_NP PTHREAD_MUTEX_RECURSIVE
 #endif