diff --git a/meson.build b/meson.build
index 99035d2306..84656cdc7e 100644
--- a/meson.build
+++ b/meson.build
@@ -423,11 +423,9 @@ decl_headers = '''
 #include <linux/fib_rules.h>
 #include <sys/stat.h>
 '''
-# FIXME: key_serial_t is only defined in keyutils.h, this is bound to fail
 
 foreach decl : ['char16_t',
                 'char32_t',
-                'key_serial_t',
                 'struct ethtool_link_settings',
                 'struct fib_rule_uid_range',
                 'struct statx',
diff --git a/src/basic/missing.h b/src/basic/missing.h
index 9044683b15..477992fbcb 100644
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -1183,9 +1183,7 @@ struct input_mask {
 #define KEY_ALS_TOGGLE 0x230
 #endif
 
-#if ! HAVE_KEY_SERIAL_T
 typedef int32_t key_serial_t;
-#endif
 
 #ifndef KEYCTL_JOIN_SESSION_KEYRING
 #define KEYCTL_JOIN_SESSION_KEYRING 1