diff --git a/CHANGES.md b/CHANGES.md
index 3cecd2c..f60e729 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,6 +2,13 @@ Changes in PDFio
 ================
 
 
+v1.5.4 - YYYY-MM-DD
+-------------------
+
+- Updated indirect reference reading code to limit the range of generation
+  numbers.
+
+
 v1.5.3 - 2025-05-03
 -------------------
 
diff --git a/configure b/configure
index 7d358bc..535b804 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.71 for pdfio 1.5.3.
+# Generated by GNU Autoconf 2.71 for pdfio 1.5.4.
 #
 # Report bugs to <https://github.com/michaelrsweet/pdfio/issues>.
 #
@@ -610,8 +610,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='pdfio'
 PACKAGE_TARNAME='pdfio'
-PACKAGE_VERSION='1.5.3'
-PACKAGE_STRING='pdfio 1.5.3'
+PACKAGE_VERSION='1.5.4'
+PACKAGE_STRING='pdfio 1.5.4'
 PACKAGE_BUGREPORT='https://github.com/michaelrsweet/pdfio/issues'
 PACKAGE_URL='https://www.msweet.org/pdfio'
 
@@ -1295,7 +1295,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures pdfio 1.5.3 to adapt to many kinds of systems.
+\`configure' configures pdfio 1.5.4 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1361,7 +1361,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of pdfio 1.5.3:";;
+     short | recursive ) echo "Configuration of pdfio 1.5.4:";;
    esac
   cat <<\_ACEOF
 
@@ -1460,7 +1460,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-pdfio configure 1.5.3
+pdfio configure 1.5.4
 generated by GNU Autoconf 2.71
 
 Copyright (C) 2021 Free Software Foundation, Inc.
@@ -1678,7 +1678,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by pdfio $as_me 1.5.3, which was
+It was created by pdfio $as_me 1.5.4, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -2434,9 +2434,9 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
-PDFIO_VERSION="1.5.3"
-PDFIO_VERSION_MAJOR="`echo 1.5.3 | awk -F. '{print $1}'`"
-PDFIO_VERSION_MINOR="`echo 1.5.3 | awk -F. '{printf("%d\n",$2);}'`"
+PDFIO_VERSION="1.5.4"
+PDFIO_VERSION_MAJOR="`echo 1.5.4 | awk -F. '{print $1}'`"
+PDFIO_VERSION_MINOR="`echo 1.5.4 | awk -F. '{printf("%d\n",$2);}'`"
 
 
 
@@ -5099,7 +5099,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by pdfio $as_me 1.5.3, which was
+This file was extended by pdfio $as_me 1.5.4, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -5155,7 +5155,7 @@ ac_cs_config_escaped=`printf "%s\n" "$ac_cs_config" | sed "s/^ //; s/'/'\\\\\\\\
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
-pdfio config.status 1.5.3
+pdfio config.status 1.5.4
 configured by $0, generated by GNU Autoconf 2.71,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 56fe973..75e9e81 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,7 @@ AC_PREREQ([2.70])
 
 
 dnl Package name and version...
-AC_INIT([pdfio], [1.5.3], [https://github.com/michaelrsweet/pdfio/issues], [pdfio], [https://www.msweet.org/pdfio])
+AC_INIT([pdfio], [1.5.4], [https://github.com/michaelrsweet/pdfio/issues], [pdfio], [https://www.msweet.org/pdfio])
 
 PDFIO_VERSION="AC_PACKAGE_VERSION"
 PDFIO_VERSION_MAJOR="`echo AC_PACKAGE_VERSION | awk -F. '{print $1}'`"
diff --git a/pdfio-value.c b/pdfio-value.c
index 767d74d..f4051f1 100644
--- a/pdfio-value.c
+++ b/pdfio-value.c
@@ -515,7 +515,7 @@ _pdfioValueRead(pdfio_file_t   *pdf,	// I - PDF file
         // Integer...
         long generation = 0;		// Generation number
 
-        while (tempptr < tb->bufend && isdigit(*tempptr & 255))
+        while (tempptr < tb->bufend && generation < 65536 && isdigit(*tempptr & 255))
         {
           generation = generation * 10 + *tempptr - '0';
           tempptr ++;
diff --git a/pdfio.h b/pdfio.h
index 3d45189..58502ee 100644
--- a/pdfio.h
+++ b/pdfio.h
@@ -23,7 +23,7 @@ extern "C" {
 // Version numbers...
 //
 
-#  define PDFIO_VERSION		"1.5.3"
+#  define PDFIO_VERSION		"1.5.4"
 #  define PDFIO_VERSION_MAJOR	1
 #  define PDFIO_VERSION_MINOR	5