diff --git a/src/insn.c b/src/insn.c
index f3f78f0..1a1a223 100644
--- a/src/insn.c
+++ b/src/insn.c
@@ -80,9 +80,19 @@ void insn_addiu(cpu_t *cpu, uint32_t insn) {
     cpu->regs[rt] = cpu->regs[rs] + imm;
 }
 
+void insn_sw(cpu_t *cpu, uint32_t insn) {
+    const uint8_t rt = RT(insn);
+    const uint8_t rs = RS(insn);
+    const uint16_t imm = IMM(insn);
+
+    debug("SW %s, [%s + %x]", REG_NAMES[rt], REG_NAMES[rt], imm);
+    cpu_write32(cpu, cpu->regs[rt], imm + cpu->regs[rs]);
+}
+
 static cpu_insn_handler primary_insn_handler[TABLE_SIZE] = {
     [LW] = insn_lw,
     [ADDIU] = insn_addiu,
+    [SW] = insn_sw,
 };
 
 static cpu_insn_handler secondary_insn_handler[TABLE_SIZE] = {