diff --git a/ports/unix/variants/mpconfigvariant_common.h b/ports/unix/variants/mpconfigvariant_common.h
index 981babca9f..2e34055bf7 100644
--- a/ports/unix/variants/mpconfigvariant_common.h
+++ b/ports/unix/variants/mpconfigvariant_common.h
@@ -41,6 +41,11 @@
 #define MICROPY_FLOAT_IMPL             (MICROPY_FLOAT_IMPL_DOUBLE)
 #endif
 
+// Don't use native _Float16 because it increases code size by a lot.
+#ifndef MICROPY_FLOAT_USE_NATIVE_FLT16
+#define MICROPY_FLOAT_USE_NATIVE_FLT16 (0)
+#endif
+
 // Enable arbitrary precision long-int by default.
 #ifndef MICROPY_LONGINT_IMPL
 #define MICROPY_LONGINT_IMPL           (MICROPY_LONGINT_IMPL_MPZ)