diff --git a/src/include/ngspice/devdefs.h b/src/include/ngspice/devdefs.h
index 3d7955935..717acb734 100644
--- a/src/include/ngspice/devdefs.h
+++ b/src/include/ngspice/devdefs.h
@@ -162,6 +162,7 @@ extern int        DEVmaxnum;    /* size of DEVices array */
 # define IOPQU(a,b,c,d)  { a, b, c|IF_SET|IF_ASK|IF_SETQUERY|IF_UNINTERESTING,\
 									d }
 # define IOPZ(a,b,c,d)  { a, b, c|IF_SET|IF_ASK|IF_CHKQUERY,		d }
+# define IOPZR(a,b,c,d)  { a, b, c|IF_SET|IF_ASK|IF_CHKQUERY|IF_REDUNDANT, d }
 # define IOPZU(a,b,c,d)  { a, b, c|IF_SET|IF_ASK|IF_CHKQUERY|IF_UNINTERESTING,\
 									d }
 # define IOPQO(a,b,c,d) { a, b, c|IF_SET|IF_ASK|IF_ORQUERY,		d }
diff --git a/src/spicelib/devices/res/res.c b/src/spicelib/devices/res/res.c
index edcb46b20..e083e7a83 100644
--- a/src/spicelib/devices/res/res.c
+++ b/src/spicelib/devices/res/res.c
@@ -45,9 +45,9 @@ IFparm RESpTable[] = { /* parameters */
 IFparm RESmPTable[] = { /* model parameters */
     IOPQ(  "rsh",    RES_MOD_RSH,      IF_REAL,"Sheet resistance"),
     IOPZ(  "narrow", RES_MOD_NARROW,   IF_REAL,"Narrowing of resistor"),
-    IOPR(  "dw",     RES_MOD_NARROW,   IF_REAL,"Narrowing of resistor"),
+    IOPZR( "dw",     RES_MOD_NARROW,   IF_REAL,"Narrowing of resistor"),
     IOPZ(  "short",  RES_MOD_SHORT,    IF_REAL,"Shortening of resistor"),
-    IOPR(  "dlr",    RES_MOD_SHORT,    IF_REAL,"Shortening of resistor"),
+    IOPZR( "dlr",    RES_MOD_SHORT,    IF_REAL,"Shortening of resistor"),
     IOPQ(  "tc1",    RES_MOD_TC1,      IF_REAL,"First order temp. coefficient"),
     IOPR(  "tc1r",   RES_MOD_TC1,      IF_REAL,"First order temp. coefficient"),
     IOPQO( "tc2",    RES_MOD_TC2,      IF_REAL,"Second order temp. coefficient"),