diff --git a/src/uxn.c b/src/uxn.c
index 0d140ff..e1a358d 100644
--- a/src/uxn.c
+++ b/src/uxn.c
@@ -64,7 +64,7 @@ void op_div(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b
 void op_and(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b & a); }
 void op_ora(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b | a); }
 void op_eor(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b ^ a); }
-void op_sft(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b >> ((a & 0x0f) % 8) << (((a & 0xf0) >> 4) % 8)); }
+void op_sft(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b >> (a & 0x07) << ((a & 0x70) >> 4)); }
 /* Stack */
 void op_lit16(Uxn *u) { u->literal += 2; }
 void op_nop16(Uxn *u) { printf("%04x\n", pop16(u->src)); }
@@ -97,7 +97,7 @@ void op_div16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->s
 void op_and16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b & a); }
 void op_ora16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b | a); }
 void op_eor16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b ^ a); }
-void op_sft16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b >> ((a & 0x000f) % 16) << (((a & 0x00f0) >> 4) % 16)); }
+void op_sft16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b >> (a & 0x000f) << ((a & 0x00f0) >> 4)); }
 
 void (*ops[])(Uxn *u) = {
 	op_brk, op_nop, op_lit, op_pop, op_dup, op_swp, op_ovr, op_rot,