diff --git a/crates/polars-core/src/frame/row/av_buffer.rs b/crates/polars-core/src/frame/row/av_buffer.rs
index 58ceb5c29784..3441166bb33f 100644
--- a/crates/polars-core/src/frame/row/av_buffer.rs
+++ b/crates/polars-core/src/frame/row/av_buffer.rs
@@ -1,5 +1,6 @@
 use std::hint::unreachable_unchecked;
 
+use arrow::bitmap::BitmapBuilder;
 #[cfg(feature = "dtype-struct")]
 use polars_utils::pl_str::PlSmallStr;
 
@@ -340,7 +341,7 @@ pub enum AnyValueBufferTrusted<'a> {
     String(StringChunkedBuilder),
     #[cfg(feature = "dtype-struct")]
     // not the trusted variant!
-    Struct(Vec<(AnyValueBuffer<'a>, PlSmallStr)>),
+    Struct(BitmapBuilder, Vec<(AnyValueBuffer<'a>, PlSmallStr)>),
     Null(NullChunkedBuilder),
     All(DataType, Vec<AnyValue<'a>>),
 }
@@ -371,7 +372,8 @@ impl<'a> AnyValueBufferTrusted<'a> {
             Float64(builder) => builder.append_null(),
             String(builder) => builder.append_null(),
             #[cfg(feature = "dtype-struct")]
-            Struct(builders) => {
+            Struct(outer_validity, builders) => {
+                outer_validity.push(false);
                 for (b, _) in builders.iter_mut() {
                     b.add(AnyValue::Null);
                 }
@@ -486,7 +488,7 @@ impl<'a> AnyValueBufferTrusted<'a> {
                         builder.append_value(v.as_str())
                     },
                     #[cfg(feature = "dtype-struct")]
-                    Struct(builders) => {
+                    Struct(outer_validity, builders) => {
                         let AnyValue::StructOwned(payload) = val else {
                             unreachable_unchecked()
                         };
@@ -501,6 +503,7 @@ impl<'a> AnyValueBufferTrusted<'a> {
                                 builder.add(av.clone());
                             }
                         }
+                        outer_validity.push(true);
                     },
                     All(_, vals) => vals.push(val.clone().into_static()),
                     _ => self.add_physical(val),
@@ -525,7 +528,7 @@ impl<'a> AnyValueBufferTrusted<'a> {
                         builder.append_value(v)
                     },
                     #[cfg(feature = "dtype-struct")]
-                    Struct(builders) => {
+                    Struct(outer_validity, builders) => {
                         let AnyValue::Struct(idx, arr, fields) = val else {
                             unreachable_unchecked()
                         };
@@ -542,6 +545,7 @@ impl<'a> AnyValueBufferTrusted<'a> {
                                 builder.add(av);
                             }
                         }
+                        outer_validity.push(true);
                     },
                     All(_, vals) => vals.push(val.clone().into_static()),
                     _ => self.add_physical(val),
@@ -619,7 +623,7 @@ impl<'a> AnyValueBufferTrusted<'a> {
                 new.finish().into_series()
             },
             #[cfg(feature = "dtype-struct")]
-            Struct(b) => {
+            Struct(outer_validity, b) => {
                 // @Q? Maybe we need to add a length parameter here for ZFS's. I am not very happy
                 // with just setting the length to zero for that case.
                 if b.is_empty() {
@@ -646,8 +650,12 @@ impl<'a> AnyValueBufferTrusted<'a> {
 
                 let length = if min_len == 0 { 0 } else { max_len };
 
+                let old_outer_validity = core::mem::take(outer_validity);
+                outer_validity.reserve(capacity);
+
                 StructChunked::from_series(PlSmallStr::EMPTY, length, v.iter())
                     .unwrap()
+                    .with_outer_validity(Some(old_outer_validity.freeze()))
                     .into_series()
             },
             Null(b) => {
@@ -716,6 +724,7 @@ impl From<(&DataType, usize)> for AnyValueBufferTrusted<'_> {
             },
             #[cfg(feature = "dtype-struct")]
             Struct(fields) => {
+                let outer_validity = BitmapBuilder::with_capacity(len);
                 let buffers = fields
                     .iter()
                     .map(|field| {
@@ -724,7 +733,7 @@ impl From<(&DataType, usize)> for AnyValueBufferTrusted<'_> {
                         (buffer, field.name.clone())
                     })
                     .collect::<Vec<_>>();
-                AnyValueBufferTrusted::Struct(buffers)
+                AnyValueBufferTrusted::Struct(outer_validity, buffers)
             },
             // List can be recursive so use AnyValues for that
             dt => AnyValueBufferTrusted::All(dt.clone(), Vec::with_capacity(len)),
diff --git a/py-polars/tests/unit/operations/test_pivot.py b/py-polars/tests/unit/operations/test_pivot.py
index 94c48244225a..c2d453cd4e41 100644
--- a/py-polars/tests/unit/operations/test_pivot.py
+++ b/py-polars/tests/unit/operations/test_pivot.py
@@ -473,22 +473,22 @@ def test_pivot_struct() -> None:
         "id": ["a", "b", "c"],
         "1": [
             {"num1": 1, "num2": 4},
-            {"num1": None, "num2": None},
+            None,
             {"num1": 6, "num2": 6},
         ],
         "2": [
             {"num1": 3, "num2": 5},
-            {"num1": None, "num2": None},
-            {"num1": None, "num2": None},
+            None,
+            None,
         ],
         "3": [
-            {"num1": None, "num2": None},
+            None,
             {"num1": 5, "num2": 3},
             {"num1": 3, "num2": 6},
         ],
         "4": [
-            {"num1": None, "num2": None},
-            {"num1": None, "num2": None},
+            None,
+            None,
             {"num1": 4, "num2": 4},
         ],
     }