diff --git a/src/frontend/A32/decoder/thumb32.inc b/src/frontend/A32/decoder/thumb32.inc
index fb17c5e3..9da07c30 100644
--- a/src/frontend/A32/decoder/thumb32.inc
+++ b/src/frontend/A32/decoder/thumb32.inc
@@ -203,7 +203,7 @@ INST(thumb32_SXTB16,         "SXTB16",                   "11111010001011111111dd
 INST(thumb32_SXTAB16,        "SXTAB16",                  "111110100010nnnn1111dddd10rrmmmm")
 INST(thumb32_UXTB16,         "UXTB16",                   "11111010001111111111dddd10rrmmmm")
 INST(thumb32_UXTAB16,        "UXTAB16",                  "111110100011nnnn1111dddd10rrmmmm")
-//INST(thumb32_SXTB,           "SXTB",                     "11111010010011111111----1-------")
+INST(thumb32_SXTB,           "SXTB",                     "11111010010011111111dddd10rrmmmm")
 //INST(thumb32_SXTAB,          "SXTAB",                    "111110100100----1111----1-------")
 //INST(thumb32_UXTB,           "UXTB",                     "11111010010111111111----1-------")
 //INST(thumb32_UXTAB,          "UXTAB",                    "111110100101----1111----1-------")
diff --git a/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp b/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp
index bfab403b..e8c4358f 100644
--- a/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp
+++ b/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp
@@ -11,6 +11,18 @@ static IR::U32 Rotate(A32::IREmitter& ir, Reg m, SignExtendRotation rotate) {
     return ir.RotateRight(ir.GetRegister(m), ir.Imm8(rotate_by), ir.Imm1(0)).result;
 }
 
+bool ThumbTranslatorVisitor::thumb32_SXTB(Reg d, SignExtendRotation rotate, Reg m) {
+    if (d == Reg::PC || m == Reg::PC) {
+        return UnpredictableInstruction();
+    }
+
+    const auto rotated = Rotate(ir, m, rotate);
+    const auto result = ir.SignExtendByteToWord(ir.LeastSignificantByte(rotated));
+
+    ir.SetRegister(d, result);
+    return true;
+}
+
 bool ThumbTranslatorVisitor::thumb32_SXTB16(Reg d, SignExtendRotation rotate, Reg m) {
     if (d == Reg::PC || m == Reg::PC) {
         return UnpredictableInstruction();
diff --git a/src/frontend/A32/translate/impl/translate_thumb.h b/src/frontend/A32/translate/impl/translate_thumb.h
index 6ac684d8..a40a07cc 100644
--- a/src/frontend/A32/translate/impl/translate_thumb.h
+++ b/src/frontend/A32/translate/impl/translate_thumb.h
@@ -122,6 +122,7 @@ struct ThumbTranslatorVisitor final {
     bool thumb32_UDF();
 
     // thumb32 data processing (register) instructions
+    bool thumb32_SXTB(Reg d, SignExtendRotation rotate, Reg m);
     bool thumb32_SXTB16(Reg d, SignExtendRotation rotate, Reg m);
     bool thumb32_SXTAB16(Reg n, Reg d, SignExtendRotation rotate, Reg m);
     bool thumb32_SXTH(Reg d, SignExtendRotation rotate, Reg m);