diff --git a/src/flag.rs b/src/flag.rs
index d82c0f5..942482e 100644
--- a/src/flag.rs
+++ b/src/flag.rs
@@ -190,6 +190,7 @@ bitflags! {
         const PTRACE_STOP_SIGNAL = 0x0000_0000_0000_0008;
         const PTRACE_STOP_BREAKPOINT = 0x0000_0000_0000_0010;
         const PTRACE_STOP_EXIT = 0x0000_0000_0000_0020;
+        const PTRACE_STOP_EXEC = 0x0000_0000_0000_0040;
         const PTRACE_STOP_MASK = 0x0000_0000_0000_00FF;
 
         const PTRACE_EVENT_CLONE = 0x0000_0000_0000_0100;