diff --git a/instr/instrs.h b/instr/instrs.h
index 6562f54..081b5d8 100644
--- a/instr/instrs.h
+++ b/instr/instrs.h
@@ -3,6 +3,10 @@
 
 #include "arch.h"
 
+#define IMPL_START_0(name)                                                  \
+void i_##name(ctx_t *ctx, acc_t *p1, acc_t *p2)                             \
+{                                                                           \
+
 #define IMPL_START_1(name)                                                  \
 void i_##name(ctx_t *ctx, acc_t *p1, acc_t *p2)                             \
 {                                                                           \