diff --git a/ChangeLog b/ChangeLog
index 92f3e6a59..37d05aca9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-11-16  Robert Larice
+ * src/frontend/parse-bison.y ,
+ * src/spicelib/parser/inpptree-parser.y ,
+ * src/xspice/xspice.c ,
+ * src/xspice/cm/cmexport.c :
+    convert macro `U()' to `IGNORE()'
+
 2010-11-16  Robert Larice
  * src/**/* :
     pour `IGNORE()' all over the source
diff --git a/src/frontend/parse-bison.y b/src/frontend/parse-bison.y
index f1fff6da1..01a766609 100644
--- a/src/frontend/parse-bison.y
+++ b/src/frontend/parse-bison.y
@@ -30,7 +30,7 @@
   # define __func__ __FUNCTION__ /* __func__ is C99, but MSC can't */
   #endif
 
-  #define U(x)  (void)x
+
 %}
 
 %name-prefix="PP"
diff --git a/src/spicelib/parser/inpptree-parser.y b/src/spicelib/parser/inpptree-parser.y
index b9d56f815..28d8c7680 100644
--- a/src/spicelib/parser/inpptree-parser.y
+++ b/src/spicelib/parser/inpptree-parser.y
@@ -12,7 +12,7 @@
   # define __func__ __FUNCTION__ /* __func__ is C99, but MSC can't */
   #endif
 
-  #define U(x)  (void)x
+
 %}
 
 %name-prefix="PT"
@@ -110,6 +110,9 @@ nonempty_arglist:
 static void
 PTerror (char **line, struct INPparseNode **retval, void *ckt, char const *s)
 {
-  U(line); U(retval); U(ckt);
+  IGNORE(line);
+  IGNORE(retval);
+  IGNORE(ckt);
+
   fprintf (stderr, "%s: %s\n", __func__, s);
 }
diff --git a/src/xspice/cm/cmexport.c b/src/xspice/cm/cmexport.c
index 287d2ea64..8b198b98b 100755
--- a/src/xspice/cm/cmexport.c
+++ b/src/xspice/cm/cmexport.c
@@ -3,8 +3,6 @@
 #include <cm.h>
 #include <dllitf.h>
 
-#define U(x)  (void)x
-
 /*how annoying!, needed for structure below*/
 static void *tcalloc(size_t a, size_t b) {
   return tmalloc(a*b);          /* FIXME, tcalloc must zero !?!? */
@@ -12,7 +10,7 @@ static void *tcalloc(size_t a, size_t b) {
 
 #ifdef HAVE_LIBGC
 static void no_free(void *p) {
-  U(p);
+  IGNORE(p);
 }
 #endif
 
diff --git a/src/xspice/xspice.c b/src/xspice/xspice.c
index c0a301709..6f9d36deb 100755
--- a/src/xspice/xspice.c
+++ b/src/xspice/xspice.c
@@ -3,15 +3,13 @@
 #include <cm.h>
 #include <dllitf.h>
 
-#define U(x)  (void)x
-
 /*how annoying!, needed for structure below*/
 static void *tcalloc(size_t a, size_t b) {
   return tmalloc(a*b);          /* FIXME, tcalloc must zero !?!? */
 }
 
 static void no_free(void *p) {
-  U(p);
+  IGNORE(p);
 }
 
 static FILE * no_file(void) {