diff --git a/src/spicelib/devices/bsim4/b4reliability.c b/src/spicelib/devices/bsim4/b4reliability.c
index 354cfda59..0b2fa36b1 100644
--- a/src/spicelib/devices/bsim4/b4reliability.c
+++ b/src/spicelib/devices/bsim4/b4reliability.c
@@ -12,23 +12,22 @@ listInsert (BSIM4vgsList **list, double vgs)
 {
     BSIM4vgsList *current, *previous ;
 
-    /* Loop until the end of the list */
-    previous = NULL ;
-    current = *list ;
-    while (current != NULL)
-    {
-        previous = current ;
-        current = current->next ;
-    }
+    /* create a new 'list' or add an element.
+    'last' contains the address of the last element */
+    if (*list)
+        previous = (*list)->last;
+    else
+        previous = NULL;
 
     /* Insert the new element into the list */
     if (previous == NULL)
     {
-        *list = TMALLOC (BSIM4vgsList, 1) ;
-        current = *list ;
-    } else {
-        current = TMALLOC (BSIM4vgsList, 1) ;
-        previous->next = current ;
+        *list = TMALLOC(BSIM4vgsList, 1);
+        (*list)->last = current = *list;
+    }
+    else {
+        current = TMALLOC(BSIM4vgsList, 1);
+        (*list)->last = previous->next = current;
     }
 
     /* Populate the element */
diff --git a/src/spicelib/devices/bsim4/bsim4def.h b/src/spicelib/devices/bsim4/bsim4def.h
index 0eac70157..a807174b8 100644
--- a/src/spicelib/devices/bsim4/bsim4def.h
+++ b/src/spicelib/devices/bsim4/bsim4def.h
@@ -35,6 +35,7 @@ Modified by Pankaj Kumar Thakur, 07/23/2012
 typedef struct sBSIM4vgsList {
     double vgs ;
     struct sBSIM4vgsList *next ;
+    struct sBSIM4vgsList *last ;
 } BSIM4vgsList ;
 #endif
 
diff --git a/src/spicelib/devices/relmodel/relmodelcalcaging.c b/src/spicelib/devices/relmodel/relmodelcalcaging.c
index 25abb7ae8..6caa6a0ab 100644
--- a/src/spicelib/devices/relmodel/relmodelcalcaging.c
+++ b/src/spicelib/devices/relmodel/relmodelcalcaging.c
@@ -19,23 +19,21 @@ listInsert (RELMODELrelList **list, double time, double deltaVth)
     RELMODELrelList *current ;
     RELMODELrelList *previous ;
 
-    /* Loop until the end of the list */
-    previous = NULL ;
-    current = *list ;
-    while (current != NULL)
-    {
-        previous = current ;
-        current = current->next ;
-    }
+    /* create a new 'list' or add an element. 
+    'last' contains the address of the last element */
+    if (*list)
+        previous = (*list)->last;
+    else
+        previous = NULL;
 
     /* Insert the new element into the list */
     if (previous == NULL)
     {
         *list = TMALLOC (RELMODELrelList, 1) ;
-        current = *list ;
+        (*list)->last = current = *list ;
     } else {
         current = TMALLOC (RELMODELrelList, 1) ;
-        previous->next = current ;
+        (*list)->last = previous->next = current ;
     }
 
     /* Populate the element */
diff --git a/src/spicelib/devices/relmodel/relmodeldefs.h b/src/spicelib/devices/relmodel/relmodeldefs.h
index 5226540c9..efe96a66e 100644
--- a/src/spicelib/devices/relmodel/relmodeldefs.h
+++ b/src/spicelib/devices/relmodel/relmodeldefs.h
@@ -15,6 +15,7 @@ typedef struct sRELMODELrelList {
     double time ;
     double deltaVth ;
     struct sRELMODELrelList *next ;
+    struct sRELMODELrelList *last ;
 } RELMODELrelList ;
 
 typedef struct sRELMODELrelStruct {