diff --git a/src/xspice/mif/mif_inp2.c b/src/xspice/mif/mif_inp2.c
index a6b48e172..aa84ff97e 100644
--- a/src/xspice/mif/mif_inp2.c
+++ b/src/xspice/mif/mif_inp2.c
@@ -846,7 +846,7 @@ MIFget_port(
 
     /* store the port type information in the instance struct */
     fast->conn[conn_num]->port[port_num]->type = def_port_type;
-    fast->conn[conn_num]->port[port_num]->type_str = def_port_type_str;
+    fast->conn[conn_num]->port[port_num]->type_str = copy(def_port_type_str);
 
     /* check for a leading tilde on digital ports */
     if(*next_token_type == MIF_TILDE_TOK) {
diff --git a/src/xspice/mif/mifsetup.c b/src/xspice/mif/mifsetup.c
index e2672e64e..275c75f13 100644
--- a/src/xspice/mif/mifsetup.c
+++ b/src/xspice/mif/mifsetup.c
@@ -528,7 +528,8 @@ MIFunsetup(GENmodel *inModel,CKTcircuit *ckt)
                     tfree(here->conn[i]->port[j]->partial);
                     tfree(here->conn[i]->port[j]->ac_gain);
                     tfree(here->conn[i]->port[j]->smp_data.input);
-
+                    /* free memory allocated in mif_inp2.c */
+                    tfree(here->conn[i]->port[j]->type_str);
                 } /* end for number of ports */
             } /* end for number of connections */
             /* free memory allocated by cm_analog_alloc and cm_analog_converge */