diff --git a/librz/core/cprint.c b/librz/core/cprint.c
index 1a351a9144f..7193e079f7e 100644
--- a/librz/core/cprint.c
+++ b/librz/core/cprint.c
@@ -548,6 +548,7 @@ static void core_handle_call(RzCore *core, char *line, char **str) {
 static char *cons_disassembly(RzCore *core, ut64 addr, ut32 byte_len, ut32 inst_len) {
 	rz_return_val_if_fail(core && (byte_len || inst_len), NULL);
 
+	// cbytes in disasm_options decides whether byte_len constrains inst_len
 	bool cbytes = true;
 
 	if (byte_len == 0) {
@@ -555,6 +556,10 @@ static char *cons_disassembly(RzCore *core, ut64 addr, ut32 byte_len, ut32 inst_
 		byte_len = inst_len;
 	}
 
+	if (inst_len == 0) {
+		inst_len = byte_len;
+	}
+
 	ut8 *block = malloc(byte_len + 1);
 	if (!block) {
 		RZ_LOG_ERROR("Cannot allocate buffer\n");