diff --git a/openscap-c99-2.patch b/openscap-c99-2.patch
new file mode 100644
index 0000000..5f7548e
--- /dev/null
+++ b/openscap-c99-2.patch
@@ -0,0 +1,25 @@
+Python bindings: Do not reuse $result for pointer conversion result
+
+The $result variable may be a pointer, but SWIG_ConvertPtr returns
+an int.  This change avoids a compilation failure with current
+compilers due to a C type error.
+
+Submitted upstream: <https://github.com/OpenSCAP/openscap/pull/2069>x
+
+diff --git a/swig/openscap.i b/swig/openscap.i
+index 219e1aa3c9ddf28b..6f29fc23c808bcfc 100644
+--- a/swig/openscap.i
++++ b/swig/openscap.i
+@@ -64,9 +64,9 @@
+ }
+ 
+ %typemap(in) void * {
+-    $result = SWIG_ConvertPtr($input,%as_voidptrptr(&$1), 0, $disown);
+-    if (!SWIG_IsOK($result)) {
+-        %argument_fail($result, "$type", $symname, $argnum);
++    int ptrres = SWIG_ConvertPtr($input,%as_voidptrptr(&$1), 0, $disown);
++    if (!SWIG_IsOK(ptrres)) {
++        %argument_fail(ptrres, "$type", $symname, $argnum);
+     }
+ }
+ 
diff --git a/openscap-c99.patch b/openscap-c99.patch
new file mode 100644
index 0000000..faa73d4
--- /dev/null
+++ b/openscap-c99.patch
@@ -0,0 +1,41 @@
+Fix type of libxml2 error callback function
+
+Current libxml2 uses void(void *user, const xmlError *error),
+previously void(void *user, xmlError *error) was used.  Switch the
+function definition to the current type and add a cast to avoid
+incompatible-pointer-types errors with newer compilers building
+against older libxml2.
+
+Submitted upstream: <https://github.com/OpenSCAP/openscap/pull/2069>x
+
+diff --git a/src/source/validate.c b/src/source/validate.c
+index da8c46dcb185c3fe..ffc54f55031746fc 100644
+--- a/src/source/validate.c
++++ b/src/source/validate.c
+@@ -46,7 +46,7 @@ struct ctxt {
+ 	char *filename;
+ };
+ 
+-static void oscap_xml_validity_handler(void *user, xmlErrorPtr error)
++static void oscap_xml_validity_handler(void *user, const xmlError *error)
+ {
+ 	struct ctxt * context = (struct ctxt *) user;
+ 
+@@ -111,7 +111,7 @@ static inline int oscap_validate_xml(struct oscap_source *source, const char *sc
+ 		goto cleanup;
+ 	}
+ 
+-	xmlSchemaSetParserStructuredErrors(parser_ctxt, oscap_xml_validity_handler, &context);
++	xmlSchemaSetParserStructuredErrors(parser_ctxt, (xmlStructuredErrorFunc) oscap_xml_validity_handler, &context);
+ 
+ 	schema = xmlSchemaParse(parser_ctxt);
+ 	if (schema == NULL) {
+@@ -125,7 +125,7 @@ static inline int oscap_validate_xml(struct oscap_source *source, const char *sc
+ 		goto cleanup;
+ 	}
+ 
+-	xmlSchemaSetValidStructuredErrors(ctxt, oscap_xml_validity_handler, &context);
++	xmlSchemaSetValidStructuredErrors(ctxt, (xmlStructuredErrorFunc) oscap_xml_validity_handler, &context);
+ 
+ 	doc = oscap_source_get_xmlDoc(source);
+ 	if (!doc)
diff --git a/openscap.spec b/openscap.spec
index 7394c36..a82f59c 100644
--- a/openscap.spec
+++ b/openscap.spec
@@ -1,6 +1,6 @@
 Name:           openscap
 Version:        1.3.9
-Release:        3%{?dist}
+Release:        4%{?dist}
 Epoch:          1
 Summary:        Set of open source libraries enabling integration of the SCAP line of standards
 License:        LGPL-2.1-or-later
@@ -21,6 +21,8 @@ Patch2:         openscap-1.3.9-includes.patch
 
 # Fix test test_sysctl_probe_all.sh
 Patch3: openscap-1.3.10-fix_sysctl_probe_tests-PR-2050.patch
+Patch4: openscap-c99.patch
+Patch5: openscap-c99-2.patch
 
 BuildRequires:  make
 BuildRequires:  cmake >= 2.6
@@ -275,6 +277,9 @@ find $RPM_BUILD_ROOT -name '*.la' -exec rm -f {} ';'
 %{_mandir}/man8/oscap-podman.8*
 
 %changelog
+* Wed Jan 03 2024 Florian Weimer <fweimer@redhat.com> - 1:1.3.9-4
+- Fix C compatibility issues
+
 * Wed Dec 20 2023 Jan Černý <jcerny@redhat.com> - 1:1.3.9-3
 - Fix test test_sysctl_probe_all.sh
 - Clean up the repository