diff --git a/src/cmd/asm/internal/asm/operand_test.go b/src/cmd/asm/internal/asm/operand_test.go
index ca692bf828..f4ce4fe114 100644
--- a/src/cmd/asm/internal/asm/operand_test.go
+++ b/src/cmd/asm/internal/asm/operand_test.go
@@ -626,7 +626,7 @@ var mips64OperandTests = []operandTest{
 	{"LO", "LO"},
 	{"a(FP)", "a(FP)"},
 	{"g", "g"},
-	{"RSB", "RSB"},
+	{"RSB", "R28"},
 	{"ret+8(FP)", "ret+8(FP)"},
 	{"runtime·abort(SB)", "runtime.abort(SB)"},
 	{"·AddUint32(SB)", "\"\".AddUint32(SB)"},
@@ -697,6 +697,7 @@ var mipsOperandTests = []operandTest{
 	{"R25", "R25"},
 	{"R26", "R26"},
 	{"R27", "R27"},
+	{"R28", "R28"},
 	{"R29", "R29"},
 	{"R3", "R3"},
 	{"R31", "R31"},
diff --git a/src/cmd/internal/obj/mips/list0.go b/src/cmd/internal/obj/mips/list0.go
index bdd9df974a..addf9f70d8 100644
--- a/src/cmd/internal/obj/mips/list0.go
+++ b/src/cmd/internal/obj/mips/list0.go
@@ -47,10 +47,6 @@ func rconv(r int) string {
 		// Special case.
 		return "g"
 	}
-	if r == REGSB {
-		// Special case.
-		return "RSB"
-	}
 	if REG_R0 <= r && r <= REG_R31 {
 		return fmt.Sprintf("R%d", r-REG_R0)
 	}