diff --git a/sys/src/ape/lib/ap/plan9/lib.h b/sys/src/ape/lib/ap/plan9/lib.h
index 91a51d5d3..a87e87b87 100644
--- a/sys/src/ape/lib/ap/plan9/lib.h
+++ b/sys/src/ape/lib/ap/plan9/lib.h
@@ -44,7 +44,7 @@ typedef struct Fdinfo{
 #define FD_BUFFEREDX	0x8
 #define FD_ISTTY	0x20
 
-#define MAXSIG SIGUSR2
+#define MAXSIG SIGPROF
 
 extern Fdinfo	_fdinfo[];