diff --git a/src/common/sizer.cpp b/src/common/sizer.cpp
index 651af1c48f..d34ad21eec 100644
--- a/src/common/sizer.cpp
+++ b/src/common/sizer.cpp
@@ -2071,7 +2071,10 @@ wxSizerItem *wxBoxSizer::DoInsert(size_t index, wxSizerItem *item)
             );
         }
 
-        if ( flags & wxEXPAND )
+        // Note that using alignment with wxEXPAND can make sense if wxSHAPED
+        // is also used, as the item doesn't necessarily fully expand in the
+        // other direction in this case.
+        if ( (flags & wxEXPAND) && !(flags & wxSHAPED) )
         {
             wxASSERT_MSG
             (
@@ -2097,7 +2100,7 @@ wxSizerItem *wxBoxSizer::DoInsert(size_t index, wxSizerItem *item)
             );
         }
 
-        if ( flags & wxEXPAND )
+        if ( (flags & wxEXPAND) && !(flags & wxSHAPED) )
         {
             wxASSERT_MSG(
                 !(flags & (wxALIGN_BOTTOM | wxALIGN_CENTRE_VERTICAL)),
diff --git a/tests/sizers/boxsizer.cpp b/tests/sizers/boxsizer.cpp
index 403e74703a..f7df2d95c8 100644
--- a/tests/sizers/boxsizer.cpp
+++ b/tests/sizers/boxsizer.cpp
@@ -398,6 +398,15 @@ TEST_CASE_METHOD(BoxSizerTestCase, "BoxSizer::IncompatibleFlags", "[sizer]")
     ASSERT_SIZER_INCOMPATIBLE_FLAGS(wxEXPAND, wxALIGN_CENTRE_VERTICAL);
     ASSERT_SIZER_INCOMPATIBLE_FLAGS(wxEXPAND, wxALIGN_BOTTOM);
 
+    // But combining it with these flags and wxSHAPED does make sense and so
+    // shouldn't result in an assert.
+    CHECK_NOTHROW(
+        sizer->Add(10, 10, 0, wxEXPAND | wxSHAPED | wxALIGN_CENTRE_VERTICAL)
+    );
+    CHECK_NOTHROW(
+        sizer->Add(10, 10, 0, wxEXPAND | wxSHAPED | wxALIGN_TOP)
+    );
+
 
     // And now exactly the same thing in the other direction.
     sizer = new wxBoxSizer(wxVERTICAL);
@@ -419,6 +428,13 @@ TEST_CASE_METHOD(BoxSizerTestCase, "BoxSizer::IncompatibleFlags", "[sizer]")
     ASSERT_SIZER_INCOMPATIBLE_FLAGS(wxEXPAND, wxALIGN_CENTRE_HORIZONTAL);
     ASSERT_SIZER_INCOMPATIBLE_FLAGS(wxEXPAND, wxALIGN_RIGHT);
 
+    CHECK_NOTHROW(
+        sizer->Add(10, 10, 0, wxEXPAND | wxSHAPED | wxALIGN_CENTRE_HORIZONTAL)
+    );
+    CHECK_NOTHROW(
+        sizer->Add(10, 10, 0, wxEXPAND | wxSHAPED | wxALIGN_RIGHT)
+    );
+
 #undef ASSERT_SIZER_INCOMPATIBLE_FLAGS
 #undef ASSERT_SIZER_INVALID_FLAGS
 }