diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index e8c6661306..5cb4a00af1 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -991,7 +991,7 @@ proc genAddr(p: BProc, e: PNode, d: var TLoc) =
   else:
     let ssoStrSub = p.config.isDefined("nimsso") and e[0].kind == nkBracketExpr and
         e[0][0].typ.skipTypes(abstractVar).kind == tyString
-    var a: TLoc = initLocExpr(p, e[0], if ssoStrSub: {lfEnforceDeref} else: {})
+    var a: TLoc = initLocExpr(p, e[0], if ssoStrSub: {lfEnforceDeref, lfPrepareForMutation} else: {})
     if e[0].kind in {nkHiddenStdConv, nkHiddenSubConv, nkConv} and not ignoreConv(e[0]):
       # addr (conv x) introduces a temp because `conv x` is not a rvalue
       # transform addr ( conv ( x ) ) -> conv ( addr ( x ) )
@@ -2809,7 +2809,7 @@ proc genWasMoved(p: BProc; n: PNode) =
     #  [addrLoc(p.config, a), getTypeDesc(p.module, a.t)])
 
 proc genMove(p: BProc; n: PNode; d: var TLoc) =
-  var a: TLoc = initLocExpr(p, n[1].skipAddr, {lfEnforceDeref})
+  var a: TLoc = initLocExpr(p, n[1].skipAddr, {lfEnforceDeref, lfPrepareForMutation})
   if n.len == 4:
     # generated by liftdestructors:
     var src: TLoc = initLocExpr(p, n[2])