diff --git a/src/unix/bsd/mod.rs b/src/unix/bsd/mod.rs
index 1d408b0a339e..1b8f58d294d2 100644
--- a/src/unix/bsd/mod.rs
+++ b/src/unix/bsd/mod.rs
@@ -865,6 +865,10 @@ cfg_if! {
     // on iOS and macOS).
     if #[cfg(not(any(target_os = "tvos", target_os = "watchos")))] {
         extern "C" {
+            #[cfg_attr(
+                target_os = "openbsd",
+                deprecated(since = "0.2.190", note = "Removed in OpenBSD 7.5")
+            )]
             pub fn syscall(num: c_int, ...) -> c_int;
         }
     }
diff --git a/src/unix/bsd/netbsdlike/mod.rs b/src/unix/bsd/netbsdlike/mod.rs
index c46a9550aca4..7d94297d8154 100644
--- a/src/unix/bsd/netbsdlike/mod.rs
+++ b/src/unix/bsd/netbsdlike/mod.rs
@@ -713,6 +713,10 @@ extern "C" {
         addrlen: *mut crate::socklen_t,
         flags: c_int,
     ) -> c_int;
+    #[cfg_attr(
+        target_os = "openbsd",
+        deprecated(since = "0.2.190", note = "Removed in OpenBSD 6.5")
+    )]
     pub fn mincore(addr: *mut c_void, len: size_t, vec: *mut c_char) -> c_int;
     #[cfg_attr(target_os = "netbsd", link_name = "__clock_getres50")]
     pub fn clock_getres(clk_id: crate::clockid_t, tp: *mut crate::timespec) -> c_int;
diff --git a/src/unix/bsd/netbsdlike/openbsd/mod.rs b/src/unix/bsd/netbsdlike/openbsd/mod.rs
index cd6f9854cfb2..883dbaee0857 100644
--- a/src/unix/bsd/netbsdlike/openbsd/mod.rs
+++ b/src/unix/bsd/netbsdlike/openbsd/mod.rs
@@ -1407,6 +1407,7 @@ pub const KERN_MALLOCSTATS: c_int = 39;
 pub const KERN_CPTIME: c_int = 40;
 pub const KERN_NCHSTATS: c_int = 41;
 pub const KERN_FORKSTAT: c_int = 42;
+#[deprecated(since = "0.2.190", note = "Removed in OpenBSD 7.2")]
 pub const KERN_NSELCOLL: c_int = 43;
 pub const KERN_TTY: c_int = 44;
 pub const KERN_CCPU: c_int = 45;