diff --git a/src/cmd/ksh93/README b/src/cmd/ksh93/README
index 0af651c48..b41a23f84 100644
--- a/src/cmd/ksh93/README
+++ b/src/cmd/ksh93/README
@@ -279,7 +279,7 @@ failures (crashes, and/or important functionality does not work).
 *	NetBSD 9.2 on x86_64
 *	OpenBSD 6.8 on x86_64
 	OpenBSD 7.0 on x86_64
-**	QNX 6.5.0 on i386
+*	QNX Neutrino 6.5.0 on i386
 *	Solaris 11.4 (gcc) on x86_64
 	Solaris 11.4 (Solaris Studio 12.5 cc) on x86_64
 *	UnixWare 7.1.4 on x86
diff --git a/src/lib/libast/features/standards b/src/lib/libast/features/standards
index 6f3b000cf..68e21c32e 100644
--- a/src/lib/libast/features/standards
+++ b/src/lib/libast/features/standards
@@ -165,6 +165,22 @@ elif tst note{ GNU (glibc) or Cygwin }end compile{
 		#endif
 		#define basename	basename	/* avoid string.h defining this in conflict with AST basename(3) */
 	}
+elif tst note{ QNX }end compile{
+		/*
+		 * QNX Neutrino, tested on version 6.5.0 as of April 2022.
+		 */
+		#define _QNX_SOURCE	1
+		#if !__QNX__
+		#error not QNX
+		#endif
+	}end {
+		#ifndef _QNX_SOURCE
+		#define _QNX_SOURCE	1
+		#endif
+		#ifndef _FILE_OFFSET_BITS
+		#define _FILE_OFFSET_BITS 64
+		#endif
+	}
 elif tst note{ _ALL_SOURCE & _POSIX_SOURCE & _POSIX_C_SOURCE & _XOPEN_SOURCE & __EXTENSIONS__ works }end compile{
 		#define _ALL_SOURCE	1
 		#define _POSIX_SOURCE	1