diff --git a/include/instructions.h b/include/instructions.h
index b8216ff..59aa6b1 100644
--- a/include/instructions.h
+++ b/include/instructions.h
@@ -118,5 +118,6 @@ public:
   void add_rm32_imm(int imm_flag);
   void or_rm32_imm(int imm_flag);
   void adc_rm32_imm(int imm_flag);
+  void sbb_rm32_imm(int imm_flag);
   void cmp_rm32_imm8();
 };
diff --git a/instructions.cpp b/instructions.cpp
index 4fcf3ce..f0e7e8f 100644
--- a/instructions.cpp
+++ b/instructions.cpp
@@ -1175,7 +1175,7 @@ void Instructions::opcode_81(){
       adc_rm32_imm(IMM32);
       break;
     case 3:
-      // TODO: sbb_rm32_imm32();
+      sbb_rm32_imm(IMM32);
       break;
     case 4:
       // TODO: and_rm32_imm32();
@@ -1211,7 +1211,7 @@ void Instructions::opcode_83(){
       adc_rm32_imm(IMM8);
       break;
     case 3:
-      // TODO: sbb_rm32_imm8();
+      sbb_rm32_imm(IMM8);
       break;
     case 4:
       // TODO: and_rm32_imm8();
@@ -1532,6 +1532,24 @@ void Instructions::adc_rm32_imm(int imm_flag){
   this->eip++;
 }
 
+void Instructions::sbb_rm32_imm(int imm_flag){
+  //printf("sbb_rm32_imm called.\n");
+
+  this->eip++;
+
+  if(imm_flag == IMM8){
+    uint8_t imm8 = memory.read_uint8(this->eip);
+    this->registers[this->M] -= imm8 + get_flag(CF);
+  } else if(imm_flag == IMM32){
+    uint32_t imm32 = memory.read_uint32(this->eip);
+    imm32 = swap_endian32(imm32);
+    this->registers[this->M] -= imm32 + get_flag(CF);
+  } else {
+  }
+
+  this->eip++;
+}
+
 void Instructions::cmp_rm32_imm8(){
   //printf("cmp_rm32_imm8 called.\n");