diff --git a/libtests/sparse_array.cc b/libtests/sparse_array.cc
index 9f31c96f..47fe8c26 100644
--- a/libtests/sparse_array.cc
+++ b/libtests/sparse_array.cc
@@ -1,8 +1,10 @@
 #include <qpdf/assert_test.h>
 
+#include <qpdf/QPDF.hh>
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/QPDFObject_private.hh>
 #include <qpdf/QPDF_Array.hh>
+
 #include <iostream>
 
 int
@@ -83,6 +85,37 @@ main()
     assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
     assert(a.at(2).isString() && (a.at(2).getStringValue() == "potato"));
 
+    QPDF pdf;
+    pdf.emptyPDF();
+
+    obj = QPDF_Array::create({10, "null"_qpdf.getObj()}, true);
+    QPDF_Array& b = *obj->as<QPDF_Array>();
+    b.setAt(5, pdf.getObject(5, 0));
+    b.setAt(7, "[0 1 2 3]"_qpdf);
+    assert(b.at(3).isNull());
+    assert(b.at(8).isNull());
+    assert(b.at(5).isIndirect());
+    assert(b.unparse() == "[ null null null null null 5 0 R null [ 0 1 2 3 ] null null ]");
+    auto c = b.copy(true);
+    auto d = b.copy(false);
+    b.at(7).setArrayItem(2, "42"_qpdf);
+    assert(c->unparse() == "[ null null null null null 5 0 R null [ 0 1 42 3 ] null null ]");
+    assert(d->unparse() == "[ null null null null null 5 0 R null [ 0 1 2 3 ] null null ]");
+
+    try {
+        b.setAt(3, {});
+        std::cout << "inserted uninitialized object\n";
+    } catch (std::logic_error&) {
+    }
+    QPDF pdf2;
+    pdf2.emptyPDF();
+    try {
+        pdf.makeIndirectObject(obj);
+        b.setAt(3, pdf2.getObject(1, 0));
+        std::cout << "inserted uninitialized object\n";
+    } catch (std::logic_error&) {
+    }
+
     std::cout << "sparse array tests done" << std::endl;
     return 0;
 }