diff --git a/doc/libpkgconf-client.rst b/doc/libpkgconf-client.rst
index 9f131e3..5ec7d62 100644
--- a/doc/libpkgconf-client.rst
+++ b/doc/libpkgconf-client.rst
@@ -88,6 +88,15 @@ thread boundaries.
    :return: true if the error handler processed the message, else false.
    :rtype: bool
 
+.. c:function:: bool pkgconf_warn(const pkgconf_client_t *client, const char *format, ...)
+
+   Report an error to a client-registered warn handler.
+
+   :param pkgconf_client_t* client: The pkgconf client object to report the error to.
+   :param char* format: A printf-style format string to use for formatting the warning message.
+   :return: true if the warn handler processed the message, else false.
+   :rtype: bool
+
 .. c:function:: bool pkgconf_default_error_handler(const char *msg, const pkgconf_client_t *client, const void *data)
 
    The default pkgconf error handler.
diff --git a/libpkgconf/client.c b/libpkgconf/client.c
index 463acff..ad617fd 100644
--- a/libpkgconf/client.c
+++ b/libpkgconf/client.c
@@ -244,6 +244,31 @@ pkgconf_error(const pkgconf_client_t *client, const char *format, ...)
 	return client->error_handler(errbuf, client, client->error_handler_data);
 }
 
+/*
+ * !doc
+ *
+ * .. c:function:: bool pkgconf_warn(const pkgconf_client_t *client, const char *format, ...)
+ *
+ *    Report an error to a client-registered warn handler.
+ *
+ *    :param pkgconf_client_t* client: The pkgconf client object to report the error to.
+ *    :param char* format: A printf-style format string to use for formatting the warning message.
+ *    :return: true if the warn handler processed the message, else false.
+ *    :rtype: bool
+ */
+bool
+pkgconf_warn(const pkgconf_client_t *client, const char *format, ...)
+{
+	char errbuf[PKGCONF_BUFSIZE];
+	va_list va;
+
+	va_start(va, format);
+	vsnprintf(errbuf, sizeof errbuf, format, va);
+	va_end(va);
+
+	return client->warn_handler(errbuf, client, client->warn_handler_data);
+}
+
 /*
  * !doc
  *
diff --git a/libpkgconf/libpkgconf.h b/libpkgconf/libpkgconf.h
index 1e3fa06..bf7e940 100644
--- a/libpkgconf/libpkgconf.h
+++ b/libpkgconf/libpkgconf.h
@@ -213,6 +213,7 @@ void pkgconf_client_set_error_handler(pkgconf_client_t *client, pkgconf_error_ha
 #endif /* defined(__INTEL_COMPILER) || defined(__GNUC__) */
 
 bool pkgconf_error(const pkgconf_client_t *client, const char *format, ...) PRINTFLIKE(2, 3);
+bool pkgconf_warn(const pkgconf_client_t *client, const char *format, ...) PRINTFLIKE(2, 3);
 bool pkgconf_default_error_handler(const char *msg, const pkgconf_client_t *client, const void *data);
 
 pkgconf_pkg_t *pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg);