diff --git a/src/arm/isa-inlines.h b/src/arm/isa-inlines.h
index cfdd73410..f9a8daf9d 100644
--- a/src/arm/isa-inlines.h
+++ b/src/arm/isa-inlines.h
@@ -91,4 +91,15 @@ static inline void _ARMReadCPSR(struct ARMCore* cpu) {
 	cpu->irqh.readCPSR(cpu);
 }
 
+static inline uint32_t _ARMPCAddress(struct ARMCore* cpu) {
+	int instructionLength;
+	enum ExecutionMode mode = cpu->cpsr.t;
+	if (mode == MODE_ARM) {
+		instructionLength = WORD_SIZE_ARM;
+	} else {
+		instructionLength = WORD_SIZE_THUMB;
+	}
+	return cpu->gprs[ARM_PC] - instructionLength * 2;
+}
+
 #endif
diff --git a/src/gba/gba.c b/src/gba/gba.c
index 86201dbe4..92d438735 100644
--- a/src/gba/gba.c
+++ b/src/gba/gba.c
@@ -628,7 +628,7 @@ void GBAHitStub(struct ARMCore* cpu, uint32_t opcode) {
 	if (gba->debugger) {
 		level = GBA_LOG_STUB;
 		struct DebuggerEntryInfo info = {
-			.address = cpu->gprs[ARM_PC],
+			.address = _ARMPCAddress(cpu),
 			.opcode = opcode
 		};
 		ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_ILLEGAL_OP, &info);
@@ -641,7 +641,7 @@ void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {
 	GBALog(gba, GBA_LOG_WARN, "Illegal opcode: %08x", opcode);
 	if (gba->debugger) {
 		struct DebuggerEntryInfo info = {
-			.address = cpu->gprs[ARM_PC],
+			.address = _ARMPCAddress(cpu),
 			.opcode = opcode
 		};
 		ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_ILLEGAL_OP, &info);