Index: flang/lib/Optimizer/HLFIR/Transforms/OptimizedBufferization.cpp
===================================================================
--- flang/lib/Optimizer/HLFIR/Transforms/OptimizedBufferization.cpp
+++ flang/lib/Optimizer/HLFIR/Transforms/OptimizedBufferization.cpp
@@ -459,9 +459,10 @@
 
 mlir::LogicalResult BroadcastAssignBufferization::matchAndRewrite(
     hlfir::AssignOp assign, mlir::PatternRewriter &rewriter) const {
-  if (assign.isAllocatableAssignment())
-    return rewriter.notifyMatchFailure(assign, "AssignOp may imply allocation");
-
+  // Since RHS is a scalar and LHS is an array, LHS must be allocated
+  // in a conforming Fortran program, and LHS cannot be reallocated
+  // as a result of the assignment. So we can ignore isAllocatableAssignment
+  // and do the transformation always.
   mlir::Value rhs = assign.getRhs();
   if (!fir::isa_trivial(rhs.getType()))
     return rewriter.notifyMatchFailure(
Index: flang/test/HLFIR/opt-scalar-assign.fir
===================================================================
--- flang/test/HLFIR/opt-scalar-assign.fir
+++ flang/test/HLFIR/opt-scalar-assign.fir
@@ -86,9 +86,19 @@
 }
 // CHECK-LABEL:   func.func @_QPtest3(
 // CHECK-SAME:                        %[[VAL_0:.*]]: !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {fir.bindc_name = "x"}) {
-// CHECK:           %[[VAL_1:.*]] = arith.constant 0 : i32
-// CHECK:           %[[VAL_2:.*]]:2 = hlfir.declare %[[VAL_0]] {fortran_attrs = #fir.var_attrs<allocatable>, uniq_name = "_QFtest3Ex"} : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>)
-// CHECK:           hlfir.assign %[[VAL_1]] to %[[VAL_2]]#0 realloc : i32, !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
+// CHECK:           %[[VAL_1:.*]] = arith.constant 1 : index
+// CHECK:           %[[VAL_2:.*]] = arith.constant 0 : index
+// CHECK:           %[[VAL_3:.*]] = arith.constant 0 : i32
+// CHECK:           %[[VAL_4:.*]]:2 = hlfir.declare %[[VAL_0]] {fortran_attrs = #fir.var_attrs<allocatable>, uniq_name = "_QFtest3Ex"} : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>)
+// CHECK:           %[[VAL_5:.*]] = fir.load %[[VAL_4]]#0 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
+// CHECK:           %[[VAL_6:.*]]:3 = fir.box_dims %[[VAL_5]], %[[VAL_2]] : (!fir.box<!fir.heap<!fir.array<?xi32>>>, index) -> (index, index, index)
+// CHECK:           fir.do_loop %[[VAL_7:.*]] = %[[VAL_1]] to %[[VAL_6]]#1 step %[[VAL_1]] unordered {
+// CHECK:             %[[VAL_8:.*]]:3 = fir.box_dims %[[VAL_5]], %[[VAL_2]] : (!fir.box<!fir.heap<!fir.array<?xi32>>>, index) -> (index, index, index)
+// CHECK:             %[[VAL_9:.*]] = arith.subi %[[VAL_8]]#0, %[[VAL_1]] : index
+// CHECK:             %[[VAL_10:.*]] = arith.addi %[[VAL_7]], %[[VAL_9]] : index
+// CHECK:             %[[VAL_11:.*]] = hlfir.designate %[[VAL_5]] (%[[VAL_10]])  : (!fir.box<!fir.heap<!fir.array<?xi32>>>, index) -> !fir.ref<i32>
+// CHECK:             hlfir.assign %[[VAL_3]] to %[[VAL_11]] : i32, !fir.ref<i32>
+// CHECK:           }
 // CHECK:           return
 // CHECK:         }