diff --git a/include/openvpn-plugin.h.in b/include/openvpn-plugin.h.in
index 5b64cbb5..103844f7 100644
--- a/include/openvpn-plugin.h.in
+++ b/include/openvpn-plugin.h.in
@@ -219,10 +219,11 @@ struct openvpn_plugin_string_list
  *           OpenVPN to plug-ins.
  *
  *    4      Exported secure_memzero() as plugin_secure_memzero()
- *           Exported openvpn_base64_encode() as plugin_base64_encode()
+ *
+ *    5      Exported openvpn_base64_encode() as plugin_base64_encode()
  *           Exported openvpn_base64_decode() as plugin_base64_decode()
  */
-#define OPENVPN_PLUGINv3_STRUCTVER 4
+#define OPENVPN_PLUGINv3_STRUCTVER 5
 
 /**
  * Definitions needed for the plug-in callback functions.
diff --git a/src/plugins/auth-pam/auth-pam.c b/src/plugins/auth-pam/auth-pam.c
index 3d564a9d..1324307f 100644
--- a/src/plugins/auth-pam/auth-pam.c
+++ b/src/plugins/auth-pam/auth-pam.c
@@ -356,8 +356,8 @@ openvpn_plugin_open_v3(const int v3structver,
     const char **argv = args->argv;
     const char **envp = args->envp;
 
-    /* Check API compatibility -- struct version 4 or higher needed */
-    if (v3structver < 4)
+    /* Check API compatibility -- struct version 5 or higher needed */
+    if (v3structver < 5)
     {
         fprintf(stderr, "AUTH-PAM: This plugin is incompatible with the running version of OpenVPN\n");
         return OPENVPN_PLUGIN_FUNC_ERROR;