diff --git a/lib/libpam/modules/pam_exec/pam_exec.c b/lib/libpam/modules/pam_exec/pam_exec.c
index cb820fbac3ef..b8f2e1d8fdfc 100644
--- a/lib/libpam/modules/pam_exec/pam_exec.c
+++ b/lib/libpam/modules/pam_exec/pam_exec.c
@@ -219,7 +219,8 @@ _pam_exec(pam_handle_t *pamh,
 		pam_err = pam_get_item(pamh, pam_item_env[i].item, &item);
 		if (pam_err != PAM_SUCCESS || item == NULL)
 			continue;
-		if (asprintf(&envstr, "%s=%s", pam_item_env[i].name, item) < 0)
+		if (asprintf(&envstr, "%s=%s", pam_item_env[i].name,
+		    (const char *)item) < 0)
 			OUT(PAM_BUF_ERR);
 		envlist[envlen++] = envstr;
 		envlist[envlen] = NULL;