diff --git a/cddl/lib/libdtrace/psinfo.d b/cddl/lib/libdtrace/psinfo.d
--- a/cddl/lib/libdtrace/psinfo.d
+++ b/cddl/lib/libdtrace/psinfo.d
@@ -55,7 +55,7 @@
 	pr_uid = T->p_ucred->cr_ruid;
 	pr_euid = T->p_ucred->cr_uid;
 	pr_gid = T->p_ucred->cr_rgid;
-	pr_egid = T->p_ucred->cr_groups[0];
+	pr_egid = T->p_ucred->cr_gid;
 	pr_addr = 0;
 	pr_psargs = (T->p_args == 0) ? "" :
 	    memstr(T->p_args->ar_args, ' ', T->p_args->ar_length);