diff --git a/sim/mips/ChangeLog b/sim/mips/ChangeLog
index 20ba0ff131..dae00e7d34 100644
--- a/sim/mips/ChangeLog
+++ b/sim/mips/ChangeLog
@@ -1,3 +1,7 @@
+2016-11-11  Mike Frysinger  <vapier@gentoo.org>
+
+	* mips.igen (check_u64): Enable for `r3900'.
+
 2016-02-05  Mike Frysinger  <vapier@gentoo.org>
 
 	* configure.ac (sim_engine_run): Change sd->base.prog_bfd to
diff --git a/sim/mips/mips.igen b/sim/mips/mips.igen
index 53370bf3dc..522cad6fe4 100644
--- a/sim/mips/mips.igen
+++ b/sim/mips/mips.igen
@@ -496,6 +496,7 @@
 *vr5000:
 *vr5400:
 *vr5500:
+*r3900:
 {
   // The check should be similar to mips64 for any with PX/UX bit equivalents.
 }