diff --git a/src/flag.rs b/src/flag.rs
index 3268ceb..e6c4cbf 100644
--- a/src/flag.rs
+++ b/src/flag.rs
@@ -68,6 +68,7 @@ pub const PROT_READ: usize = 0x0004_0000;
 pub const PTRACE_CONT: u8 = 0b0000_0001;
 pub const PTRACE_SINGLESTEP: u8 = 0b0000_0010;
 pub const PTRACE_SYSCALL: u8 = 0b0000_0011;
+pub const PTRACE_WAIT: u8 = 0b0000_0100;
 pub const PTRACE_OPERATIONMASK: u8 = 0b0000_1111;
 pub const PTRACE_SYSEMU: u8 = 0b0001_0000;