diff --git a/herd/tests/instructions/AArch64.self/NORUN b/herd/tests/instructions/AArch64.self/NORUN
index 193557484..5a8dbaf03 100644
--- a/herd/tests/instructions/AArch64.self/NORUN
+++ b/herd/tests/instructions/AArch64.self/NORUN
@@ -13,3 +13,5 @@ S15
 S16
 S17
 S23
+#This test faults on non-existing instruction
+S20
diff --git a/herd/tests/instructions/AArch64/A236.litmus b/herd/tests/instructions/AArch64/A236.litmus
index ce6131165..77ab95e8d 100644
--- a/herd/tests/instructions/AArch64/A236.litmus
+++ b/herd/tests/instructions/AArch64/A236.litmus
@@ -1,4 +1,4 @@
-AArch64 236
+AArch64 A236
 
 (* Tests MVN Register instruction *)
 (* Remember inverting 00 -> 11 which is 0 to -1 in 2s complement *)
diff --git a/herd/tests/instructions/AArch64/A236.litmus.expected b/herd/tests/instructions/AArch64/A236.litmus.expected
index 4bf2b9653..7daa97b73 100644
--- a/herd/tests/instructions/AArch64/A236.litmus.expected
+++ b/herd/tests/instructions/AArch64/A236.litmus.expected
@@ -1,10 +1,10 @@
-Test 236 Required
+Test A236 Required
 States 1
 0:X0=-1; 0:X3=-2;
 Ok
 Witnesses
 Positive: 1 Negative: 0
 Condition forall (0:X0=-1 /\ 0:X3=-2)
-Observation 236 Always 1 0
+Observation A236 Always 1 0
 Hash=8205eb706c7f2a58368a8bdc3b855c37
 
diff --git a/herd/tests/instructions/AArch64/L086.litmus b/herd/tests/instructions/AArch64/L086.litmus
index fb8bebcac..1d52b3fc3 100644
--- a/herd/tests/instructions/AArch64/L086.litmus
+++ b/herd/tests/instructions/AArch64/L086.litmus
@@ -1,4 +1,6 @@
 AArch64 L086
+(* Allocate register X1 to X1 *)
+Stable=X1
 {
 0:X0=instr:"ADR X1,.+0";
 }
@@ -8,4 +10,4 @@ L0:           ;
   LDR W2,[X1] ;
   CMP W0,W2   ;
   CSET W3,EQ  ;
-forall 0:X3=1  
\ No newline at end of file
+forall 0:X3=1