diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
index ad586cab7c4f3..bc579a0eeb435 100644
--- a/flang/lib/Lower/ConvertVariable.cpp
+++ b/flang/lib/Lower/ConvertVariable.cpp
@@ -625,6 +625,11 @@ mustBeDefaultInitializedAtRuntime(const Fortran::lower::pft::Variable &var) {
     return false;
   if (Fortran::semantics::IsDummy(sym) && !Fortran::semantics::IsIntentOut(sym))
     return false;
+  // Polymorphic intent(out) dummy might need default initialization
+  // at runtime.
+  if (Fortran::semantics::IsPolymorphic(sym) &&
+      Fortran::semantics::IsDummy(sym) && Fortran::semantics::IsIntentOut(sym))
+    return true;
   // Local variables (including function results), and intent(out) dummies must
   // be default initialized at runtime if their type has default initialization.
   return hasDefaultInitialization(sym);
diff --git a/flang/test/Lower/polymorphic.f90 b/flang/test/Lower/polymorphic.f90
index bd31cc75f8051..48c54a012c532 100644
--- a/flang/test/Lower/polymorphic.f90
+++ b/flang/test/Lower/polymorphic.f90
@@ -23,7 +23,7 @@ module polymorphic_test
   end type
 
   type, extends(p1) :: p2
-    real :: c
+    real :: c = 10.5
   end type
 
   type r1
@@ -738,6 +738,24 @@ subroutine test_unlimited_polymorphic_alloc_array_ret()
 ! CHECK: %[[RES:.*]] = fir.call @_QMpolymorphic_testPunlimited_polymorphic_alloc_array_ret() fastmath<contract> : () -> !fir.class<!fir.heap<!fir.array<?xnone>>>
 ! CHECK: fir.save_result %[[RES]] to %[[RES_TMP]] : !fir.class<!fir.heap<!fir.array<?xnone>>>, !fir.ref<!fir.class<!fir.heap<!fir.array<?xnone>>>>
 
+  subroutine test_unlimited_polymorphic_intentout(a)
+    class(*), intent(out) :: a
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMpolymorphic_testPtest_unlimited_polymorphic_intentout(
+! CHECK-SAME: %[[ARG0:.*]]: !fir.class<none> {fir.bindc_name = "a"}) {
+! CHECK: %[[BOX_NONE:.*]] = fir.convert %[[ARG0]] : (!fir.class<none>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAInitialize(%[[BOX_NONE]], %{{.*}}, %{{.*}}) {{.*}} : (!fir.box<none>, !fir.ref<i8>, i32) -> none
+
+  subroutine test_polymorphic_intentout(a)
+    class(p1), intent(out) :: a
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMpolymorphic_testPtest_polymorphic_intentout(
+! CHECK-SAME: %[[ARG0:.*]]: !fir.class<!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>> {fir.bindc_name = "a"}) {
+! CHECK: %[[BOX_NONE:.*]] = fir.convert %[[ARG0]] : (!fir.class<!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAInitialize(%[[BOX_NONE]], %{{.*}}, %{{.*}}) {{.*}} : (!fir.box<none>, !fir.ref<i8>, i32) -> none
+
 end module
 
 program test