diff --git a/src/execute.c b/src/execute.c
index 42846b3..9edeb74 100644
--- a/src/execute.c
+++ b/src/execute.c
@@ -17,6 +17,7 @@
 // Prototypes
 void execute_SDT(Machine *state, a64inst_instruction *inst);
 void execute_Branch(Machine *state, a64inst_instruction *inst);
+void executeMultiply(Machine *state, a64inst_instruction *inst);
 
 // Return maximum of two dwords
 static dword max(dword a, dword b) {
@@ -328,7 +329,10 @@ void execute(Machine *state, a64inst_instruction *inst) {
 
         // Execute a data processing register instruction
         case a64inst_DPREGISTER:
-            executeDPRegister(state, inst);
+            if (inst->data.DPRegisterData.DPROpType == a64inst_DPR_MULTIPLY)
+                executeMultiply(state, inst);
+            else
+                executeDPRegister(state, inst);
             break;
 
         case a64inst_SINGLETRANSFER: 
@@ -426,3 +430,9 @@ void execute_Branch(Machine *state, a64inst_instruction *inst) {
             break;
     }
 }
+
+void executeMultiply(Machine *state, a64inst_instruction *inst) {
+    dword product = state->registers[inst->data.DPRegisterData.src1] * state->registers[inst->data.DPRegisterData.src2];
+    dword sum = readRegister(state, inst->data.DPRegisterData.processOpData.multiplydata.summand, inst->data.DPRegisterData.regType) + (inst->data.DPRegisterData.processOpData.multiplydata.negProd ? -product : product);
+    writeRegister(state, inst->data.DPRegisterData.dest, inst->data.DPRegisterData.regType, sum);
+}