diff --git a/libc-test/build.rs b/libc-test/build.rs
index af19881210efc1d52d0125523f2003884e51f8c2..5d915e13412fda412a53c8e412b1bf4c014717e6 100644
--- a/libc-test/build.rs
+++ b/libc-test/build.rs
@@ -1379,6 +1379,12 @@ fn test_android(target: &str) {
             // FIXME: deprecated: not available in any header
             // See: https://github.com/rust-lang/libc/issues/1356
             "ENOATTR" => true,
+
+            // FIXME: still necessary?
+            "SIG_DFL" | "SIG_ERR" | "SIG_IGN" => true, // sighandler_t weirdness
+            // FIXME: still necessary?
+            "SIGUNUSED" => true, // removed in glibc 2.26
+
             _ => false,
         }
     });
diff --git a/src/unix/notbsd/android/mod.rs b/src/unix/notbsd/android/mod.rs
index 51a2cafd9f99aa34691c56e162813fbd90e58924..b6b67842905ccf79d8e4d4023130be8bf8d062ef 100644
--- a/src/unix/notbsd/android/mod.rs
+++ b/src/unix/notbsd/android/mod.rs
@@ -1792,7 +1792,10 @@ pub const SIOCSIFMAP: ::c_ulong = 0x00008971;
 pub const MODULE_INIT_IGNORE_MODVERSIONS: ::c_uint = 0x0001;
 pub const MODULE_INIT_IGNORE_VERMAGIC: ::c_uint = 0x0002;
 
-// Similarity to Linux it's not used but defined for compatibility.
+#[deprecated(
+    since = "0.2.55",
+    note = "ENOATTR is not available on Android; use ENODATA instead"
+)]
 pub const ENOATTR: ::c_int = ::ENODATA;
 
 // linux/if_alg.h
diff --git a/src/unix/notbsd/linux/mod.rs b/src/unix/notbsd/linux/mod.rs
index 71e2c37629ae9b08413d2c0740f776fe9c6788e8..a76f7a0283cbb8aa5cabca1b4da99223c4c88bdb 100644
--- a/src/unix/notbsd/linux/mod.rs
+++ b/src/unix/notbsd/linux/mod.rs
@@ -1409,9 +1409,10 @@ pub const FALLOC_FL_ZERO_RANGE: ::c_int = 0x10;
 pub const FALLOC_FL_INSERT_RANGE: ::c_int = 0x20;
 pub const FALLOC_FL_UNSHARE_RANGE: ::c_int = 0x40;
 
-// On Linux, libc doesn't define this constant, libattr does instead.
-// We still define it for Linux as it's defined by libc on other platforms,
-// and it's mentioned in the man pages for getxattr and setxattr.
+#[deprecated(
+    since = "0.2.55",
+    note = "ENOATTR is not available on Linux; use ENODATA instead"
+)]
 pub const ENOATTR: ::c_int = ::ENODATA;
 
 pub const SO_ORIGINAL_DST: ::c_int = 80;