diff --git a/test/fixedbugs/issue11656.go b/test/fixedbugs/issue11656.go
index 50182633645..acd3f4f3e5d 100644
--- a/test/fixedbugs/issue11656.go
+++ b/test/fixedbugs/issue11656.go
@@ -27,13 +27,6 @@ import (
 )
 
 func main() {
-	// This test is currently failing on some architectures.
-	// See issue #43283.
-	switch runtime.GOARCH {
-	case "ppc64", "mips", "mipsle", "mips64", "mips64le":
-		return
-	}
-
 	debug.SetPanicOnFault(true)
 	defer func() {
 		if err := recover(); err == nil {
@@ -61,27 +54,30 @@ func f(n int) {
 		x uintptr
 	}
 
-	// We want to force an illegal instruction, to get a crash
-	// at a PC value != 0.
+	// We want to force a seg fault, to get a crash at a PC value != 0.
 	// Not all systems make the data section non-executable.
 	ill := make([]byte, 64)
 	switch runtime.GOARCH {
 	case "386", "amd64":
-		binary.LittleEndian.PutUint16(ill, 0x0b0f) // ud2
+		ill = append(ill, 0x89, 0x04, 0x25, 0x00, 0x00, 0x00, 0x00) // MOVL AX, 0
 	case "arm":
-		binary.LittleEndian.PutUint32(ill, 0xe7f000f0) // no name, but permanently undefined
+		binary.LittleEndian.PutUint32(ill, 0xe3a00000) // MOVW $0, R0
+		binary.LittleEndian.PutUint32(ill, 0xe5800000) // MOVW R0, (R0)
 	case "arm64":
-		binary.LittleEndian.PutUint32(ill, 0xd4207d00) // brk #1000
+		binary.LittleEndian.PutUint32(ill, 0xf90003ff) // MOVD ZR, (ZR)
 	case "ppc64":
-		binary.BigEndian.PutUint32(ill, 0x7fe00008) // trap
+		binary.BigEndian.PutUint32(ill, 0xf8000000) // MOVD R0, (R0)
 	case "ppc64le":
-		binary.LittleEndian.PutUint32(ill, 0x7fe00008) // trap
+		binary.LittleEndian.PutUint32(ill, 0xf8000000) // MOVD R0, (R0)
 	case "mips", "mips64":
-		binary.BigEndian.PutUint32(ill, 0x00000034) // trap
+		binary.BigEndian.PutUint32(ill, 0xfc000000) // MOVV R0, (R0)
 	case "mipsle", "mips64le":
-		binary.LittleEndian.PutUint32(ill, 0x00000034) // trap
+		binary.LittleEndian.PutUint32(ill, 0xfc000000) // MOVV R0, (R0)
 	case "s390x":
-		binary.BigEndian.PutUint32(ill, 0) // undefined instruction
+		ill = append(ill, 0xa7, 0x09, 0x00, 0x00)             // MOVD $0, R0
+		ill = append(ill, 0xe3, 0x00, 0x00, 0x00, 0x00, 0x24) // MOVD R0, (R0)
+	case "riscv64":
+		binary.LittleEndian.PutUint32(ill, 0x00003023) // MOV X0, (X0)
 	default:
 		// Just leave it as 0 and hope for the best.
 	}