diff --git a/src/util/pty_compat.cc b/src/util/pty_compat.cc
index 98fa22a..25c0abf 100644
--- a/src/util/pty_compat.cc
+++ b/src/util/pty_compat.cc
@@ -62,7 +62,7 @@ pid_t my_forkpty( int *amaster, char *name,
 
   master = open( PTY_DEVICE, O_RDWR | O_NOCTTY );
   if ( master < 0 ) {
-    perror( "open("PTY_DEVICE")" );
+    perror( "open(" PTY_DEVICE ")" );
     return -1;
   }