diff --git a/src/cmd/asm/internal/asm/testdata/arm64.s b/src/cmd/asm/internal/asm/testdata/arm64.s
index c7564726e6..6a44f0f5b0 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64.s
@@ -287,6 +287,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	HINT $0                                 // 1f2003d5
 	DMB	$1
 	SVC
+	SB                                      // ff3003d5
 
 // encryption
 	SHA256H	V9.S4, V3, V2                   // 6240095e
diff --git a/src/cmd/asm/internal/asm/testdata/arm64enc.s b/src/cmd/asm/internal/asm/testdata/arm64enc.s
index cc002a1584..dca6c78de4 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64enc.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64enc.s
@@ -762,5 +762,6 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$-8
 	VMOV V0.B[1], R11                                           // 0b3c030e
 	VMOV V1.H[3], R12                                           // 2c3c0e0e
 	VUSHR $6, V22.H8, V23.H8                                    // d7061a6f
+	SB                                                          // ff3003d5
 
 	RET
diff --git a/src/cmd/asm/internal/asm/testdata/arm64error.s b/src/cmd/asm/internal/asm/testdata/arm64error.s
index ce88e3ca54..71c025ca55 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64error.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64error.s
@@ -428,4 +428,5 @@ TEXT errors(SB),$0
 	AUTIBSP	C                                                // ERROR "illegal combination"
 	AUTIA1716	$45                                      // ERROR "illegal combination"
 	AUTIB1716	R0                                       // ERROR "illegal combination"
+	SB	$1                                               // ERROR "illegal combination"
 	RET