diff --git a/src/spicelib/devices/mos6/Makefile.am b/src/spicelib/devices/mos6/Makefile.am
index 5161dbac3..324030804 100644
--- a/src/spicelib/devices/mos6/Makefile.am
+++ b/src/spicelib/devices/mos6/Makefile.am
@@ -7,6 +7,7 @@ libmos6_la_SOURCES =	\
 	mos6ask.c	\
 	mos6conv.c	\
 	mos6defs.h	\
+	mos6del.c	\
 	mos6dest.c	\
 	mos6ext.h	\
 	mos6ic.c	\
@@ -15,6 +16,7 @@ libmos6_la_SOURCES =	\
 	mos6itf.h	\
 	mos6load.c	\
 	mos6mask.c	\
+	mos6mdel.c	\
 	mos6mpar.c	\
 	mos6par.c	\
 	mos6set.c	\
diff --git a/src/spicelib/devices/mos6/mos6del.c b/src/spicelib/devices/mos6/mos6del.c
new file mode 100644
index 000000000..7185a22e0
--- /dev/null
+++ b/src/spicelib/devices/mos6/mos6del.c
@@ -0,0 +1,29 @@
+/**********
+Copyright 1990 Regents of the University of California.  All rights reserved.
+Author: 1985 Thomas L. Quarles
+**********/
+
+#include "ngspice/ngspice.h"
+#include "mos6defs.h"
+#include "ngspice/sperror.h"
+#include "ngspice/suffix.h"
+
+
+int
+MOS6delete(GENmodel *model, IFuid name, GENinstance **kill)
+{
+    for (; model; model = model->GENnextModel) {
+        GENinstance **prev = &(model->GENinstances);
+        GENinstance *here = *prev;
+        for (; here; here = *prev) {
+            if (here->GENname == name || (kill && here == *kill)) {
+                *prev = here->GENnextInstance;
+                GENinstanceFree(here);
+                return OK;
+            }
+            prev = &(here->GENnextInstance);
+        }
+    }
+
+    return E_NODEV;
+}
diff --git a/src/spicelib/devices/mos6/mos6init.c b/src/spicelib/devices/mos6/mos6init.c
index 65df0328c..c87370016 100644
--- a/src/spicelib/devices/mos6/mos6init.c
+++ b/src/spicelib/devices/mos6/mos6init.c
@@ -52,8 +52,8 @@ SPICEdev MOS6info = {
  /* DEVacLoad     */ NULL, /* MOS6acLoad, XXX */
  /* DEVaccept     */ NULL,
  /* DEVdestroy    */ MOS6destroy,
- /* DEVmodDelete  */ NULL,
- /* DEVdelete     */ NULL,
+ /* DEVmodDelete  */ MOS6mDelete,
+ /* DEVdelete     */ MOS6delete,
  /* DEVsetic      */ MOS6getic,
  /* DEVask        */ MOS6ask,
  /* DEVmodAsk     */ MOS6mAsk,
diff --git a/src/spicelib/devices/mos6/mos6mdel.c b/src/spicelib/devices/mos6/mos6mdel.c
new file mode 100644
index 000000000..da9fd6799
--- /dev/null
+++ b/src/spicelib/devices/mos6/mos6mdel.c
@@ -0,0 +1,36 @@
+/**********
+Copyright 1990 Regents of the University of California.  All rights reserved.
+Author: 1985 Thomas L. Quarles
+**********/
+
+#include "ngspice/ngspice.h"
+#include "mos6defs.h"
+#include "ngspice/sperror.h"
+#include "ngspice/suffix.h"
+
+
+int
+MOS6mDelete(GENmodel **models, IFuid modname, GENmodel *kill)
+{
+    GENinstance *here;
+    GENmodel **prev = models;
+    GENmodel *model = *prev;
+
+    for (; model; model = model->GENnextModel) {
+        if (model->GENmodName == modname || (kill && model == kill))
+            break;
+        prev = &(model->GENnextModel);
+    }
+
+    if (!model)
+        return E_NOMOD;
+
+    *prev = model->GENnextModel;
+    for (here = model->GENinstances; here;) {
+        GENinstance *next_instance = here->GENnextInstance;
+        GENinstanceFree(here);
+        here = next_instance;
+    }
+    GENmodelFree(model);
+    return OK;
+}