diff --git a/src/flag.rs b/src/flag.rs
index 6959e23bda..ef17c1703f 100644
--- a/src/flag.rs
+++ b/src/flag.rs
@@ -355,3 +355,11 @@ pub fn wexitstatus(status: usize) -> usize {
 pub fn wcoredump(status: usize) -> bool {
     (status & 0x80) != 0
 }
+
+bitflags! {
+    pub struct MremapFlags: usize {
+        const FIXED = 1;
+        const FIXED_REPLACE = 3;
+        // TODO: MAYMOVE, DONTUNMAP
+    }
+}
diff --git a/src/number.rs b/src/number.rs
index 72daf705ad..d7c911c58b 100644
--- a/src/number.rs
+++ b/src/number.rs
@@ -25,10 +25,16 @@ pub const SYS_FCHMOD: usize =     SYS_CLASS_FILE | 94;
 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;
+
+// TODO: Rename FMAP/FUNMAP to MMAP/MUNMAP
 pub const SYS_FMAP_OLD: usize =   SYS_CLASS_FILE | SYS_ARG_SLICE | 90;
 pub const SYS_FMAP: usize =       SYS_CLASS_FILE | SYS_ARG_SLICE | 900;
+// TODO: SYS_FUNMAP should be SYS_CLASS_FILE
+// TODO: Remove FMAP/FMAP_OLD
 pub const SYS_FUNMAP_OLD: usize = SYS_CLASS_FILE | 91;
 pub const SYS_FUNMAP: usize =     SYS_CLASS_FILE | 92;
+pub const SYS_MREMAP: usize = 155;
+
 pub const SYS_FPATH: usize =      SYS_CLASS_FILE | SYS_ARG_MSLICE | 928;
 pub const SYS_FRENAME: usize =    SYS_CLASS_FILE | SYS_ARG_PATH | 38;
 pub const SYS_FSTAT: usize =      SYS_CLASS_FILE | SYS_ARG_MSLICE | 28;