diff --git a/src/isa-thumb.c b/src/isa-thumb.c
index b4eb8beaa..1ab59cb61 100644
--- a/src/isa-thumb.c
+++ b/src/isa-thumb.c
@@ -168,6 +168,7 @@ DEFINE_LOAD_WITH_IMMEDIATE_THUMB(LDR, )
 DEFINE_STORE_WITH_IMMEDIATE_THUMB(STR, )
 
 DEFINE_INSTRUCTION_THUMB(ILL, )
+DEFINE_INSTRUCTION_THUMB(BX, )
 
 #define DECLARE_INSTRUCTION_THUMB(EMITTER, NAME) \
 	EMITTER ## NAME
@@ -216,8 +217,8 @@ DEFINE_INSTRUCTION_THUMB(ILL, )
 	DECLARE_INSTRUCTION_WITH_HIGH_THUMB(EMITTER, ADD4), \
 	DECLARE_INSTRUCTION_WITH_HIGH_THUMB(EMITTER, CMP3), \
 	DECLARE_INSTRUCTION_WITH_HIGH_THUMB(EMITTER, MOV3), \
-	DECLARE_INSTRUCTION_THUMB(EMITTER, ILL), \
-	DECLARE_INSTRUCTION_THUMB(EMITTER, ILL), \
+	DECLARE_INSTRUCTION_THUMB(EMITTER, BX), \
+	DECLARE_INSTRUCTION_THUMB(EMITTER, BX), \
 	DECLARE_INSTRUCTION_THUMB(EMITTER, ILL), \
 	DECLARE_INSTRUCTION_THUMB(EMITTER, ILL), \
 	APPLY(COUNT_3, DUMMY_4, DECLARE_INSTRUCTION_THUMB(EMITTER, LDR3_R)) \