diff --git a/src/flag.rs b/src/flag.rs
index f0b2f9a0e0..8d468b1b42 100644
--- a/src/flag.rs
+++ b/src/flag.rs
@@ -333,3 +333,16 @@ bitflags! {
         const INHIBIT_DELIVERY = 1;
     }
 }
+bitflags! {
+    pub struct CallFlags: usize {
+        // unused
+        const BIT0 = 1 << 0;
+        const BIT1 = 1 << 1;
+        const BIT2 = 1 << 2;
+        const BIT3 = 1 << 3;
+        const BIT4 = 1 << 4;
+        const BIT5 = 1 << 5;
+        const BIT6 = 1 << 6;
+        const BIT7 = 1 << 7;
+    }
+}
diff --git a/src/number.rs b/src/number.rs
index e2ba3a27d8..84394013e1 100644
--- a/src/number.rs
+++ b/src/number.rs
@@ -28,6 +28,9 @@ pub const SYS_FCHOWN: usize = SYS_CLASS_FILE | 207;
 pub const SYS_FCNTL: usize = SYS_CLASS_FILE | 55;
 pub const SYS_FEVENT: usize = SYS_CLASS_FILE | 927;
 
+// SYS_CALL, fd, inout buf ptr, inout buf len, flags, metadata buf ptr, metadata buf len
+pub const SYS_CALL: usize = SYS_CLASS_FILE | SYS_ARG_SLICE | SYS_ARG_MSLICE | 0xCA11;
+
 pub const SYS_SENDFD: usize = SYS_CLASS_FILE | 34;
 pub const SYS_GETDENTS: usize = SYS_CLASS_FILE | 43;
 
diff --git a/src/schemev2.rs b/src/schemev2.rs
index 43e5931473..2ab372fbe7 100644
--- a/src/schemev2.rs
+++ b/src/schemev2.rs
@@ -128,6 +128,7 @@ pub enum Opcode {
 
     Getdents = 26,
     CloseMsg = 27,
+    Call = 28,
 }
 
 impl Opcode {
@@ -166,6 +167,7 @@ impl Opcode {
             25 => Cancel,
             26 => Getdents,
             27 => CloseMsg,
+            28 => Call,
 
             _ => return None,
         })