diff --git a/ps/display.c b/ps/display.c
index 1fddbbe1..b0da9e7e 100644
--- a/ps/display.c
+++ b/ps/display.c
@@ -638,6 +638,7 @@ int main(int argc, char *argv[]){
     case SIGKILL:  /* can not catch */
     case SIGSTOP:  /* can not catch */
     case SIGWINCH: /* don't care if window size changes */
+    case SIGURG:   /* Urgent condition on socket (4.2BSD) */
       ;
     }
   } while (0);