diff --git a/plugins/sudoers/auth/pam.c b/plugins/sudoers/auth/pam.c
index ea0a5e142..ddbd46aa2 100644
--- a/plugins/sudoers/auth/pam.c
+++ b/plugins/sudoers/auth/pam.c
@@ -66,7 +66,8 @@
 #include "sudo_auth.h"
 
 /* Only OpenPAM and Linux PAM use const qualifiers. */
-#if defined(_OPENPAM) || defined(__LIBPAM_VERSION) || defined(__LINUX_PAM__)
+#if defined(_OPENPAM) || defined(OPENPAM_VERSION) || \
+    defined(__LIBPAM_VERSION) || defined(__LINUX_PAM__)
 # define PAM_CONST	const
 #else
 # define PAM_CONST