diff --git a/libs/js/nsprpub/pr/include/private/primpl.h b/libs/js/nsprpub/pr/include/private/primpl.h
index 1565d1842b..79c2543376 100644
--- a/libs/js/nsprpub/pr/include/private/primpl.h
+++ b/libs/js/nsprpub/pr/include/private/primpl.h
@@ -54,6 +54,10 @@
 #include <kernel/OS.h>
 #endif
 
+#ifdef DARWIN 
+#include <signal.h>
+#endif
+
 #ifdef WINNT
 /* Need to force service-pack 3 extensions to be defined by
 ** setting _WIN32_WINNT to NT 4.0 for winsock.h, winbase.h, winnt.h.