diff --git a/flang/lib/Lower/ConvertExpr.cpp b/flang/lib/Lower/ConvertExpr.cpp
--- a/flang/lib/Lower/ConvertExpr.cpp
+++ b/flang/lib/Lower/ConvertExpr.cpp
@@ -5495,9 +5495,15 @@
   CC genarr(const Fortran::evaluate::SetLength<KIND> &x) {
     auto lf = genarr(x.left());
     mlir::Value rhs = fir::getBase(asScalar(x.right()));
+    fir::CharBoxValue temp =
+        fir::factory::CharacterExprHelper(builder, getLoc())
+            .createCharacterTemp(
+                fir::CharacterType::getUnknownLen(builder.getContext(), KIND),
+                rhs);
     return [=](IterSpace iters) -> ExtValue {
-      mlir::Value lhs = fir::getBase(lf(iters));
-      return fir::CharBoxValue{lhs, rhs};
+      fir::factory::CharacterExprHelper(builder, getLoc())
+          .createAssign(temp, lf(iters));
+      return temp;
     };
   }
 
diff --git a/flang/test/Lower/array-expression.f90 b/flang/test/Lower/array-expression.f90
--- a/flang/test/Lower/array-expression.f90
+++ b/flang/test/Lower/array-expression.f90
@@ -994,6 +994,7 @@
 ! CHECK:         %[[VAL_24:.*]] = fir.array_load %[[VAL_5]](%[[VAL_22]]) {{\[}}%[[VAL_23]]] : (!fir.ref<!fir.array<140x!fir.char<2,13>>>, !fir.shape<1>, !fir.slice<1>) -> !fir.array<140x!fir.char<2,13>>
 ! CHECK:         %[[VAL_25:.*]] = fir.load %[[VAL_2]] : !fir.ref<i32>
 ! CHECK:         %[[VAL_26:.*]] = fir.convert %[[VAL_25]] : (i32) -> i64
+! CHECK:         %[[char_temp:.*]] = fir.alloca !fir.char<4,?>(%16 : i64) {bindc_name = ".chrtmp"}
 ! CHECK:         %[[VAL_27:.*]] = arith.constant 1 : index
 ! CHECK:         %[[VAL_28:.*]] = arith.constant 0 : index
 ! CHECK:         %[[VAL_29:.*]] = arith.subi %[[VAL_13]], %[[VAL_27]] : index
@@ -1024,7 +1025,7 @@
 ! CHECK:           %[[VAL_53:.*]] = arith.muli %[[VAL_51]], %[[VAL_52]] : i64
 ! CHECK:           %[[VAL_54:.*]] = arith.constant false
 ! CHECK:           %[[VAL_55:.*]] = fir.convert %[[VAL_46]] : (!fir.ref<!fir.char<4,?>>) -> !fir.ref<i8>
-! CHECK:           %[[VAL_56:.*]] = fir.convert %[[VAL_34]] : (!fir.ref<!fir.char<4,?>>) -> !fir.ref<i8>
+! CHECK:           %[[VAL_56:.*]] = fir.convert %[[char_temp]] : (!fir.ref<!fir.char<4,?>>) -> !fir.ref<i8>
 ! CHECK:           fir.call @llvm.memmove.p0.p0.i64(%[[VAL_55]], %[[VAL_56]], %[[VAL_53]], %[[VAL_54]]) : (!fir.ref<i8>, !fir.ref<i8>, i64, i1) -> ()
 ! CHECK:           %[[VAL_57:.*]] = arith.constant 1 : i32
 ! CHECK:           %[[VAL_58:.*]] = arith.subi %[[VAL_11]], %[[VAL_57]] : i32
diff --git a/flang/test/Lower/structure-constructors.f90 b/flang/test/Lower/structure-constructors.f90
--- a/flang/test/Lower/structure-constructors.f90
+++ b/flang/test/Lower/structure-constructors.f90
@@ -101,6 +101,7 @@
   ! CHECK: %[[VAL_14:.*]] = fir.array_load %[[VAL_11]](%[[VAL_13]]) : (!fir.ref<!fir.array<5x!fir.char<1,3>>>, !fir.shape<1>) -> !fir.array<5x!fir.char<1,3>>
   ! CHECK: %[[VAL_15:.*]] = fir.shape %[[VAL_6]] : (index) -> !fir.shape<1>
   ! CHECK: %[[VAL_16:.*]] = fir.array_load %[[VAL_5]](%[[VAL_15]]) : (!fir.ref<!fir.array<5x!fir.char<1,3>>>, !fir.shape<1>) -> !fir.array<5x!fir.char<1,3>>
+  ! CHECK: %[[char_temp:.*]] = fir.alloca !fir.char<1,3> {bindc_name = ".chrtmp"}
   ! CHECK: %[[VAL_17:.*]] = arith.constant 1 : index
   ! CHECK: %[[VAL_18:.*]] = arith.constant 0 : index
   ! CHECK: %[[VAL_19:.*]] = arith.subi %[[VAL_12]], %[[VAL_17]] : index
@@ -113,7 +114,7 @@
   ! CHECK: %[[VAL_28:.*]] = arith.muli %[[VAL_26]], %[[VAL_27]] : i64
   ! CHECK: %[[VAL_29:.*]] = arith.constant false
   ! CHECK: %[[VAL_30:.*]] = fir.convert %[[VAL_24]] : (!fir.ref<!fir.char<1,3>>) -> !fir.ref<i8>
-  ! CHECK: %[[VAL_31:.*]] = fir.convert %[[VAL_23]] : (!fir.ref<!fir.char<1,3>>) -> !fir.ref<i8>
+  ! CHECK: %[[VAL_31:.*]] = fir.convert %[[char_temp]] : (!fir.ref<!fir.char<1,3>>) -> !fir.ref<i8>
   ! CHECK: fir.call @llvm.memmove.p0.p0.i64(%[[VAL_30]], %[[VAL_31]], %[[VAL_28]], %[[VAL_29]]) : (!fir.ref<i8>, !fir.ref<i8>, i64, i1) -> ()
   ! CHECK: %[[VAL_32:.*]] = fir.array_amend %[[VAL_22]], %[[VAL_24]] : (!fir.array<5x!fir.char<1,3>>, !fir.ref<!fir.char<1,3>>) -> !fir.array<5x!fir.char<1,3>>
   ! CHECK: fir.result %[[VAL_32]] : !fir.array<5x!fir.char<1,3>>