diff --git a/src/alu.c b/src/alu.c
index 3cd9810..d08cd9a 100644
--- a/src/alu.c
+++ b/src/alu.c
@@ -491,7 +491,7 @@ static void parse_binary_literal(void)	// Now GotByte = "%" or "b"
 	}
 	if (!digits)
 		Throw_warning("Binary literal without any digits.");	// FIXME - make into error!
-	if (digits & config.warn_bin_mask)
+	if ((digits & config.warn_bin_mask) && (config.wanted_version >= VER_BACKSLASHESCAPING))
 		Throw_first_pass_warning("Binary literal with strange number of digits.");
 	// set force bits
 	if (config.honor_leading_zeroes) {