diff --git a/src/isa-thumb.c b/src/isa-thumb.c
index dcb1f8842..ce04af92c 100644
--- a/src/isa-thumb.c
+++ b/src/isa-thumb.c
@@ -73,6 +73,17 @@ DEFINE_SHIFT_1_INSTRUCTION_THUMB(LSL, )
 DEFINE_SHIFT_1_INSTRUCTION_THUMB(LSR, )
 DEFINE_SHIFT_1_INSTRUCTION_THUMB(ASR, )
 
+#define DEFINE_ADD_SUB_1_INSTRUCTION_EX_THUMB(NAME, IMMEDIATE, BODY) \
+	DEFINE_INSTRUCTION_THUMB(NAME, \
+		int immediate = IMMEDIATE; \
+		BODY;)
+
+#define DEFINE_ADD_SUB_1_INSTRUCTION_THUMB(NAME, BODY) \
+	COUNT_3(DEFINE_ADD_SUB_1_INSTRUCTION_EX_THUMB, NAME ## 1_, BODY)
+
+DEFINE_ADD_SUB_1_INSTRUCTION_THUMB(ADD, )
+DEFINE_ADD_SUB_1_INSTRUCTION_THUMB(SUB, )
+
 #define DEFINE_ADD_SUB_3_INSTRUCTION_EX_THUMB(NAME, RM, BODY) \
 	DEFINE_INSTRUCTION_THUMB(NAME, \
 		int rm = RM; \
@@ -94,6 +105,8 @@ DEFINE_ADD_SUB_3_INSTRUCTION_THUMB(SUB, )
 	APPLY(COUNT_5, DUMMY, DECLARE_INSTRUCTION_THUMB(EMITTER, ASR1_)) \
 	APPLY(COUNT_3, DUMMY, DECLARE_INSTRUCTION_THUMB(EMITTER, ADD3_R)) \
 	APPLY(COUNT_3, DUMMY, DECLARE_INSTRUCTION_THUMB(EMITTER, SUB3_R)) \
+	APPLY(COUNT_3, DUMMY, DECLARE_INSTRUCTION_THUMB(EMITTER, ADD1_)) \
+	APPLY(COUNT_3, DUMMY, DECLARE_INSTRUCTION_THUMB(EMITTER, SUB1_)) \
 
 static const ThumbInstruction _thumbTable[0x400] = {
 	DECLARE_THUMB_EMITTER_BLOCK(_ThumbInstruction)