diff --git a/src/execute.c b/src/execute.c
index 4ef7512..2d60bef 100644
--- a/src/execute.c
+++ b/src/execute.c
@@ -362,7 +362,7 @@ void execute_SDT(Machine *state, a64inst_instruction *inst) {
     if (inst->data.SingleTransferData.SingleTransferOpType == a64inst_SINGLE_TRANSFER_LOAD_LITERAL) {
         // Load Literal
         isLoad = true;
-        address = state->pc + inst->data.SingleTransferData.processOpData.loadLiteralData.offset * 4;
+        address = state->pc + signExtend(inst->data.SingleTransferData.processOpData.loadLiteralData.offset, 19) * 4;
     } else {
         address = state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.base];
         isLoad = inst->data.SingleTransferData.processOpData.singleDataTransferData.transferType == a64inst_LOAD;
@@ -374,7 +374,7 @@ void execute_SDT(Machine *state, a64inst_instruction *inst) {
                 address += state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.offsetReg];
                 break;
             case a64inst_PRE_INDEXED:
-                address += inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset;
+                address += signExtend(inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset, 9);
                 state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.base] = address;
                 break;
             case a64inst_POST_INDEXED:
@@ -395,7 +395,8 @@ void execute_SDT(Machine *state, a64inst_instruction *inst) {
 
          // Update base register if post indexed
         if (inst->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode == a64inst_POST_INDEXED) {
-            writeRegister(state, inst->data.SingleTransferData.processOpData.singleDataTransferData.base, inst->data.SingleTransferData.regType == a64inst_W,  address + inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset);
+            dword result = address + signExtend(inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset, 9);
+            writeRegister(state, inst->data.SingleTransferData.processOpData.singleDataTransferData.base, inst->data.SingleTransferData.regType == a64inst_W, result);
         }
     }