diff --git a/src/flag.rs b/src/flag.rs
index d82c0f579c793c0ab79d12e1c4e09811870b7204..942482eb3fba354ab26a1dc8f432edb01dd8e290 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;