diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -2755,7 +2755,9 @@
               // Delegate pointer association to unlimited polymorphic pointer
               // to the runtime. element size, type code, attribute and of
               // course base_addr might need to be updated.
-              if (lhsType && lhsType->IsUnlimitedPolymorphic()) {
+              if (lhsType && lhsType->IsPolymorphic()) {
+                if (explicitIterationSpace())
+                  TODO(loc, "polymorphic pointer assignment in FORALL");
                 mlir::Value lhs = genExprMutableBox(loc, assign.lhs).getAddr();
                 mlir::Value rhs =
                     fir::getBase(genExprBox(loc, assign.rhs, stmtCtx));
diff --git a/flang/test/Lower/pointer-association-polymorphic.f90 b/flang/test/Lower/pointer-association-polymorphic.f90
--- a/flang/test/Lower/pointer-association-polymorphic.f90
+++ b/flang/test/Lower/pointer-association-polymorphic.f90
@@ -85,15 +85,17 @@
 ! CHECK-DAG: %[[PA_DESC:.*]] = fir.alloca !fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>> {bindc_name = "pa", uniq_name = "_QMpolyFtest_pointerEpa"}
 
 ! CHECK: %[[C1_DESC_LOAD:.*]] = fir.load %[[C1_DESC]] : !fir.ref<!fir.class<!fir.heap<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
-! CHECK: %[[C1_REBOX:.*]] = fir.rebox %[[C1_DESC_LOAD]] : (!fir.class<!fir.heap<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
-! CHECK: fir.store %[[C1_REBOX]] to %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
+! CHECK: %[[P_CONV:.*]] = fir.convert %[[P_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[C1_DESC_CONV:.*]] = fir.convert %[[C1_DESC_LOAD]] : (!fir.class<!fir.heap<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[P_CONV]], %[[C1_DESC_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
 ! CHECK: %[[P_DESC_LOAD:.*]] = fir.load %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
 ! CHECK: %[[P_REBOX:.*]] = fir.rebox %[[P_DESC_LOAD]] : (!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
 ! CHECK: fir.dispatch "proc"(%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) (%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
 
 ! CHECK: %[[C2_DESC_LOAD:.*]] = fir.load %[[C2_DESC]] : !fir.ref<!fir.class<!fir.heap<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
-! CHECK: %[[C2_REBOX:.*]] = fir.rebox %[[C2_DESC_LOAD]] : (!fir.class<!fir.heap<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
-! CHECK: fir.store %[[C2_REBOX]] to %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
+! CHECK: %[[P_CONV:.*]] = fir.convert %[[P_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[C2_DESC_CONV:.*]] = fir.convert %[[C2_DESC_LOAD]] : (!fir.class<!fir.heap<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[P_CONV]], %[[C2_DESC_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
 ! CHECK: %[[P_DESC_LOAD:.*]] = fir.load %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
 ! CHECK: %[[P_REBOX:.*]] = fir.rebox %[[P_DESC_LOAD]] : (!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
 ! CHECK: fir.dispatch "proc"(%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) (%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
@@ -106,8 +108,10 @@
 ! CHECK: %[[IDX:.*]] = arith.subi %[[C1]], %[[LB]] : i64
 ! CHECK: %[[C3_COORD:.*]] = fir.coordinate_of %[[C3_LOAD]], %[[IDX]] : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, i64) -> !fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
 ! CHECK: %[[C3_TDESC:.*]] = fir.box_tdesc %[[C3_LOAD]] : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>) -> !fir.tdesc<none>
-! CHECK: %[[C3_EMBOX:.*]] = fir.embox %[[C3_COORD]] tdesc %[[C3_TDESC]] : (!fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>, !fir.tdesc<none>) -> !fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
-! CHECK: fir.store %[[C3_EMBOX]] to %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
+! CHECK: %[[C3_EMBOX:.*]] = fir.embox %[[C3_COORD]] tdesc %[[C3_TDESC]] : (!fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>, !fir.tdesc<none>) -> !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
+! CHECK: %[[P_CONV:.*]] = fir.convert %[[P_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[C3_EMBOX_CONV:.*]] = fir.convert %[[C3_EMBOX]] : (!fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[P_CONV]], %[[C3_EMBOX_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
 ! CHECK: %[[P_DESC_LOAD:.*]] = fir.load %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
 ! CHECK: %[[P_REBOX:.*]] = fir.rebox %[[P_DESC_LOAD]] : (!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
 ! CHECK: fir.dispatch "proc"(%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) (%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
@@ -120,15 +124,19 @@
 ! CHECK: %[[IDX:.*]] = arith.subi %[[C2]], %[[LB]] : i64
 ! CHECK: %[[C4_COORD:.*]] = fir.coordinate_of %[[C4_LOAD]], %[[IDX]] : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, i64) -> !fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
 ! CHECK: %[[C4_TDESC:.*]] = fir.box_tdesc %[[C4_LOAD]] : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>) -> !fir.tdesc<none>
-! CHECK: %[[C4_EMBOX:.*]] = fir.embox %[[C4_COORD]] tdesc %[[C4_TDESC]] : (!fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>, !fir.tdesc<none>) -> !fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
-! CHECK: fir.store %[[C4_EMBOX]] to %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
+! CHECK: %[[C4_EMBOX:.*]] = fir.embox %[[C4_COORD]] tdesc %[[C4_TDESC]] : (!fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>, !fir.tdesc<none>) -> !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
+! CHECK: %[[P_CONV:.*]] = fir.convert %[[P_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[C4_EMBOX_CONV:.*]] = fir.convert %[[C4_EMBOX]] : (!fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[P_CONV]], %[[C4_EMBOX_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
 ! CHECK: %[[P_DESC_LOAD:.*]] = fir.load %[[P_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
 ! CHECK: %[[P_REBOX:.*]] = fir.rebox %[[P_DESC_LOAD]] : (!fir.class<!fir.ptr<!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
 ! CHECK: fir.dispatch "proc"(%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) (%[[P_REBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
 
 ! CHECK: %[[C3_LOAD:.*]] = fir.load %[[C3_DESC]] : !fir.ref<!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
-! CHECK: %[[C3_REBOX:.*]] = fir.rebox %[[C3_LOAD]](%{{.*}}) : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, !fir.shift<1>) -> !fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
-! CHECK: fir.store %[[C3_REBOX]] to %[[PA_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
+! CHECK: %[[C3_REBOX:.*]] = fir.rebox %[[C3_LOAD]](%{{.*}}) : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, !fir.shift<1>) -> !fir.class<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
+! CHECK: %[[PA_CONV:.*]] = fir.convert %[[PA_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[C3_REBOX_CONV:.*]] = fir.convert %[[C3_REBOX]] : (!fir.class<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[PA_CONV]], %[[C3_REBOX_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
 ! CHECK-LABEL: fir.do_loop
 ! CHECK: %[[PA_LOAD:.*]] = fir.load %[[PA_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
 ! CHECK: %[[PA_COORD:.*]] = fir.coordinate_of %[[PA_LOAD]], %{{.*}} : (!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, i64) -> !fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
@@ -137,8 +145,10 @@
 ! CHECK: fir.dispatch "proc"(%[[PA_EMBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) (%[[PA_EMBOX]] : !fir.class<!fir.type<_QMpolyTp1{a:i32,b:i32}>>) {pass_arg_pos = 0 : i32}
 
 ! CHECK: %[[C4_LOAD:.*]] = fir.load %[[C4_DESC]] : !fir.ref<!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
-! CHECK: %[[C4_REBOX:.*]] = fir.rebox %[[C4_LOAD]](%{{.*}}) : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, !fir.shift<1>) -> !fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
-! CHECK: fir.store %[[C4_REBOX]] to %[[PA_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
+! CHECK: %[[C4_REBOX:.*]] = fir.rebox %[[C4_LOAD]](%{{.*}}) : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, !fir.shift<1>) -> !fir.class<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
+! CHECK: %[[PA_CONV:.*]] = fir.convert %[[PA_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>) -> !fir.ref<!fir.box<none>> 
+! CHECK: %[[C4_REBOX_CONV:.*]] = fir.convert %[[C4_REBOX]] : (!fir.class<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.box<none> 
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[PA_CONV]], %[[C4_REBOX_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none 
 ! CHECK-LABEL: fir.do_loop
 ! CHECK: %[[PA_LOAD:.*]] = fir.load %[[PA_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
 ! CHECK: %[[PA_COORD:.*]] = fir.coordinate_of %[[PA_LOAD]], %{{.*}} : (!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, i64) -> !fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>
@@ -158,8 +168,9 @@
 ! CHECK: %[[SHIFT:.*]] = fir.shift %[[C4_DIMS]]#0 : (index) -> !fir.shift<1>
 ! CHECK: %[[SLICE:.*]] = fir.slice %[[C2_INDEX]], %[[C4_INDEX]], %[[C1_INDEX]] : (index, index, index) -> !fir.slice<1>
 ! CHECK: %[[SLICE_REBOX:.*]] = fir.rebox %[[C4_LOAD]](%[[SHIFT]]) [%[[SLICE]]] : (!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, !fir.shift<1>, !fir.slice<1>) -> !fir.class<!fir.array<3x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>
-! CHECK: %[[PTR_REBOX:.*]] = fir.rebox %[[SLICE_REBOX]] : (!fir.class<!fir.array<3x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>
-! CHECK: fir.store %[[PTR_REBOX]] to %[[PA_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
+! CHECK: %[[PA_CONV:.*]] = fir.convert %[[PA_DESC]] : (!fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[SLICE_REBOX_CONV:.*]] = fir.convert %[[SLICE_REBOX]] : (!fir.class<!fir.array<3x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>) -> !fir.box<none> 
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[PA_CONV]], %[[SLICE_REBOX_CONV]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none 
 ! CHECK-LABEL: fir.do_loop
 ! CHECK: %[[PA_LOAD:.*]] = fir.load %[[PA_DESC]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>>
 ! CHECK: %[[PA_COORD:.*]] = fir.coordinate_of %[[PA_LOAD]], %{{.*}} : (!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolyTp1{a:i32,b:i32}>>>>, i64) -> !fir.ref<!fir.type<_QMpolyTp1{a:i32,b:i32}>>