diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 9b502e4..6a3bc80 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1465,7 +1465,7 @@ QPDF::readTrailer()
     qpdf_offset_t offset = m->file->tell();
     bool empty = false;
     auto object =
-        QPDFParser(m->file, "trailer", m->tokenizer, nullptr, this, true).parse(empty, false);
+        QPDFParser(*m->file, "trailer", m->tokenizer, nullptr, this, true).parse(empty, false);
     if (empty) {
         // Nothing in the PDF spec appears to allow empty objects, but they have been encountered in
         // actual PDF files and Adobe Reader appears to ignore them.
@@ -1488,7 +1488,7 @@ QPDF::readObject(std::string const& description, QPDFObjGen og)
     StringDecrypter decrypter{this, og};
     StringDecrypter* decrypter_ptr = m->encp->encrypted ? &decrypter : nullptr;
     auto object =
-        QPDFParser(m->file, m->last_object_description, m->tokenizer, decrypter_ptr, this, true)
+        QPDFParser(*m->file, m->last_object_description, m->tokenizer, decrypter_ptr, this, true)
             .parse(empty, false);
     if (empty) {
         // Nothing in the PDF spec appears to allow empty objects, but they have been encountered in
@@ -1608,7 +1608,7 @@ QPDF::readObjectInStream(std::shared_ptr<InputSource>& input, int obj)
     m->last_object_description += " 0";
 
     bool empty = false;
-    auto object = QPDFParser(input, m->last_object_description, m->tokenizer, nullptr, this, true)
+    auto object = QPDFParser(*input, m->last_object_description, m->tokenizer, nullptr, this, true)
                       .parse(empty, false);
     if (empty) {
         // Nothing in the PDF spec appears to allow empty objects, but they have been encountered in
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index 3ea9613..ce77526 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -2164,7 +2164,7 @@ QPDFObjectHandle::parseContentStream_data(
         qpdf_offset_t offset = input->getLastOffset();
         input->seek(offset, SEEK_SET);
         auto obj =
-            QPDFParser(input, "content", tokenizer, nullptr, context, false).parse(empty, true);
+            QPDFParser(*input, "content", tokenizer, nullptr, context, false).parse(empty, true);
         if (!obj.isInitialized()) {
             // EOF
             break;
@@ -2223,7 +2223,7 @@ QPDFObjectHandle::parse(
     StringDecrypter* decrypter,
     QPDF* context)
 {
-    return QPDFParser(input, object_description, tokenizer, decrypter, context, false)
+    return QPDFParser(*input, object_description, tokenizer, decrypter, context, false)
         .parse(empty, false);
 }
 
diff --git a/libqpdf/QPDFParser.cc b/libqpdf/QPDFParser.cc
index 08f94c6..a9d3e04 100644
--- a/libqpdf/QPDFParser.cc
+++ b/libqpdf/QPDFParser.cc
@@ -33,9 +33,9 @@ QPDFParser::parse(bool& empty, bool content_stream)
 
     QPDF::ParseGuard pg(context);
     empty = false;
-    start = input->tell();
+    start = input.tell();
 
-    if (!tokenizer.nextToken(*input, object_description)) {
+    if (!tokenizer.nextToken(input, object_description)) {
         warn(tokenizer.getErrorMessage());
     }
 
@@ -101,7 +101,7 @@ QPDFParser::parse(bool& empty, bool content_stream)
             } else if (value == "endobj") {
                 // We just saw endobj without having read anything.  Treat this as a null and do
                 // not move the input source's offset.
-                input->seek(input->getLastOffset(), SEEK_SET);
+                input.seek(input.getLastOffset(), SEEK_SET);
                 empty = true;
                 return {QPDF_Null::create()};
             } else {
@@ -138,7 +138,7 @@ QPDFParser::parseRemainder(bool content_stream)
     bool b_contents = false;
 
     while (true) {
-        if (!tokenizer.nextToken(*input, object_description)) {
+        if (!tokenizer.nextToken(input, object_description)) {
             warn(tokenizer.getErrorMessage());
         }
         ++good_count; // optimistically
@@ -151,7 +151,7 @@ QPDFParser::parseRemainder(bool content_stream)
                     // Process the oldest buffered integer.
                     addInt(int_count);
                 }
-                last_offset_buffer[int_count % 2] = input->getLastOffset();
+                last_offset_buffer[int_count % 2] = input.getLastOffset();
                 int_buffer[int_count % 2] = QUtil::string_to_ll(tokenizer.getValue().c_str());
                 continue;
 
@@ -309,7 +309,7 @@ QPDFParser::parseRemainder(bool content_stream)
         case QPDFTokenizer::tt_integer:
             if (!content_stream) {
                 // Buffer token in case it is part of an indirect reference.
-                last_offset_buffer[1] = input->getLastOffset();
+                last_offset_buffer[1] = input.getLastOffset();
                 int_buffer[1] = QUtil::string_to_ll(tokenizer.getValue().c_str());
                 int_count = 1;
             } else {
@@ -351,7 +351,7 @@ QPDFParser::parseRemainder(bool content_stream)
                 if (decrypter) {
                     if (b_contents) {
                         frame->contents_string = val;
-                        frame->contents_offset = input->getLastOffset();
+                        frame->contents_offset = input.getLastOffset();
                         b_contents = false;
                     }
                     std::string s{val};
@@ -419,7 +419,7 @@ void
 QPDFParser::addScalar(Args&&... args)
 {
     auto obj = T::create(args...);
-    obj->setDescription(context, description, input->getLastOffset());
+    obj->setDescription(context, description, input.getLastOffset());
     add(std::move(obj));
 }
 
@@ -506,11 +506,11 @@ QPDFParser::warnDuplicateKey()
 void
 QPDFParser::warn(qpdf_offset_t offset, std::string const& msg) const
 {
-    warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), object_description, offset, msg));
+    warn(QPDFExc(qpdf_e_damaged_pdf, input.getName(), object_description, offset, msg));
 }
 
 void
 QPDFParser::warn(std::string const& msg) const
 {
-    warn(input->getLastOffset(), msg);
+    warn(input.getLastOffset(), msg);
 }
diff --git a/libqpdf/qpdf/QPDFParser.hh b/libqpdf/qpdf/QPDFParser.hh
index e036b02..1eecf97 100644
--- a/libqpdf/qpdf/QPDFParser.hh
+++ b/libqpdf/qpdf/QPDFParser.hh
@@ -12,7 +12,7 @@ class QPDFParser
   public:
     QPDFParser() = delete;
     QPDFParser(
-        std::shared_ptr<InputSource> input,
+        InputSource& input,
         std::string const& object_description,
         QPDFTokenizer& tokenizer,
         QPDFObjectHandle::StringDecrypter* decrypter,
@@ -24,7 +24,7 @@ class QPDFParser
         decrypter(decrypter),
         context(context),
         description(std::make_shared<QPDFValue::Description>(
-            std::string(input->getName() + ", " + object_description + " at offset $PO"))),
+            std::string(input.getName() + ", " + object_description + " at offset $PO"))),
         parse_pdf(parse_pdf)
     {
     }
@@ -39,9 +39,9 @@ class QPDFParser
 
     struct StackFrame
     {
-        StackFrame(std::shared_ptr<InputSource> const& input, parser_state_e state) :
+        StackFrame(InputSource& input, parser_state_e state) :
             state(state),
-            offset(input->tell())
+            offset(input.tell())
         {
         }
 
@@ -72,7 +72,7 @@ class QPDFParser
     // NB the offset includes any leading whitespace.
     QPDFObjectHandle withDescription(Args&&... args);
     void setDescription(std::shared_ptr<QPDFObject>& obj, qpdf_offset_t parsed_offset);
-    std::shared_ptr<InputSource> input;
+    InputSource& input;
     std::string const& object_description;
     QPDFTokenizer& tokenizer;
     QPDFObjectHandle::StringDecrypter* decrypter;