1 files changed, 2 insertions, 0 deletions
diff --git a/mg.c b/mg.c
index 64f64978a2..69bb521363 100644
--- a/mg.c
+++ b/mg.c
@@ -2207,6 +2207,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
 #ifndef MACOS_TRADITIONAL
     case '0':
+	LOCK_DOLLARZERO_MUTEX;
 #ifdef HAS_SETPROCTITLE
 	/* The BSDs don't show the argv[] in ps(1) output, they
 	 * show a string from the process struct and provide
@@ -2286,6 +2287,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	    for (i = 1; i < PL_origargc; i++)
 		PL_origargv[i] = Nullch;
 	}
+	UNLOCK_DOLLARZERO_MUTEX;
 	break;
 #endif
     }