diff --git a/xs/tools/xslOpt.h b/xs/tools/xslOpt.h
index 8b912cb25..ad4db4ea0 100644
--- a/xs/tools/xslOpt.h
+++ b/xs/tools/xslOpt.h
@@ -91,6 +91,8 @@
 	#if GNUC > 11
 		#define mxUseFloat16 1
 	#endif
+#else
+	#define mxUseFloat16 1
 #endif
 	#define mxUseGCCAtomics 1
 	#define mxUsePOSIXThreads 1
diff --git a/xs/tools/xst.h b/xs/tools/xst.h
index f41b95d07..d55a99b51 100644
--- a/xs/tools/xst.h
+++ b/xs/tools/xst.h
@@ -85,7 +85,13 @@
 	#include <unistd.h>
 	typedef int txSocket;
 	#define mxNoSocket -1
+#if mxLinux
+	#if GNUC > 11
+		#define mxUseFloat16 1
+	#endif
+#else
 	#define mxUseFloat16 1
+#endif
 	#define mxUseGCCAtomics 1
 	#define mxUsePOSIXThreads 1
 #endif