diff --git a/makesrcdist b/makesrcdist
index 8f2e63b..ee68b08 100755
--- a/makesrcdist
+++ b/makesrcdist
@@ -2,18 +2,61 @@
 #
 # makesrcdist - make a source distribution of pdfio.
 #
+# Usage:
+#
+#   ./makesrcdist [--snapshot] VERSION
+#
 
+# Support "--snapshot" option...
+if test "$1" == "--snapshot"; then
+    shift
+    snapshot=1
+else
+    snapshot=0
+fi
+
+# Get version...
 if test $# != 1; then
-	echo "Usage: ./makesrcdist version"
-	exit 1
+    echo "Usage: ./makesrcdist [--snapshot] VERSION"
+    exit 1
 fi
 
 version=$1
 
-echo Creating tag for release...
-git tag -m "Tag $version" v$version
-git push origin v$version
+# Check that version number has been updated everywhere...
+if test $(grep AC_INIT configure.ac | awk '{print $2}') != "[$version],"; then
+    echo "Still need to update AC_INIT version in 'configure.ac'."
+    exit 1
+fi
 
+if test $(grep PDFIO_VERSION= configure | awk -F \" '{print $2}') != "$version"; then
+    echo "Still need to run 'autoconf -f'."
+    exit 1
+fi
+
+if test $(grep '<version>' pdfio_native.nuspec | sed -E -e '1,$s/^.*<version>([0-9.]+).*$/\1/') != "$version"; then
+    echo "Still need to update version in 'pdfio_native.nuspec'."
+    exit 1
+fi
+
+if test $(grep '<version>' pdfio_native.redist.nuspec | sed -E -e '1,$s/^.*<version>([0-9.]+).*$/\1/') != "$version"; then
+    echo "Still need to update version in 'pdfio_native.redist.nuspec'."
+    exit 1
+fi
+
+if test $(grep PDFIO_VERSION pdfio.h | awk -F \" '{print $2}') != "$version"; then
+    echo "Still need to update PDFIO_VERSION in 'pdfio.h'."
+    exit 1
+fi
+
+# Tag release...
+if test $snapshot = 0; then
+    echo Creating tag for release...
+    git tag -m "Tag $version" v$version
+    git push origin v$version
+fi
+
+# Make source archives...
 echo Creating pdfio-$version.tar.gz...
 git archive --format tar --prefix=pdfio-$version/ HEAD | gzip -v9 >pdfio-$version.tar.gz
 gpg --detach-sign pdfio-$version.tar.gz
diff --git a/pdfio_native.nuspec b/pdfio_native.nuspec
index df07417..9f9bd66 100644
--- a/pdfio_native.nuspec
+++ b/pdfio_native.nuspec
@@ -3,7 +3,7 @@
     <metadata>
         <id>pdfio_native</id>
         <title>PDFio Library for VS2019+</title>
-        <version>1.2.0</version>
+        <version>1.3.0</version>
         <authors>Michael R Sweet</authors>
         <owners>michaelrsweet</owners>
         <projectUrl>https://github.com/michaelrsweet/pappl</projectUrl>
@@ -16,7 +16,7 @@
         <copyright>Copyright © 2019-2024 by Michael R Sweet</copyright>
         <tags>pdf file native</tags>
 	<dependencies>
-	    <dependency id="pdfio_native.redist" version="1.2.0" />
+	    <dependency id="pdfio_native.redist" version="1.3.0" />
 	    <dependency id="zlib_native.redist" version="1.2.11" />
 	</dependencies>
     </metadata>
diff --git a/pdfio_native.redist.nuspec b/pdfio_native.redist.nuspec
index 212425d..82aec53 100644
--- a/pdfio_native.redist.nuspec
+++ b/pdfio_native.redist.nuspec
@@ -3,7 +3,7 @@
     <metadata>
         <id>pdfio_native.redist</id>
         <title>PDFio Library for VS2019+</title>
-        <version>1.2.0</version>
+        <version>1.3.0</version>
         <authors>Michael R Sweet</authors>
         <owners>michaelrsweet</owners>
         <projectUrl>https://github.com/michaelrsweet/pappl</projectUrl>