diff --git a/synth2.cc b/synth2.cc
index 6a19d81fe..a150e06ed 100644
--- a/synth2.cc
+++ b/synth2.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: synth2.cc,v 1.24 2003/03/25 04:04:29 steve Exp $"
+#ident "$Id: synth2.cc,v 1.25 2003/04/03 04:30:00 steve Exp $"
 #endif
 
 # include "config.h"
@@ -425,7 +425,7 @@ bool NetBlock::synth_sync(Design*des, NetScope*scope, NetFF*ff,
 		 otherwise used) then move the Aset input to Aclr. */
 	    if (tmp_aset.len() == ff->width()) {
 
-		  if ((aset_value2.as_ulong() == 0)
+		  if (aset_value2.is_zero()
 		      && ff2->pin_Aset().is_linked()
 		      && !ff2->pin_Aclr().is_linked()) {
 
@@ -518,7 +518,7 @@ bool NetCondit::synth_sync(Design*des, NetScope*scope, NetFF*ff,
 		  }
 
 		  assert(tmp.is_defined());
-		  if (tmp.as_ulong() == 0) {
+		  if (tmp.is_zero()) {
 			connect(ff->pin_Aclr(), ce->pin(0));
 
 		  } else {
@@ -779,6 +779,9 @@ void synth2(Design*des)
 
 /*
  * $Log: synth2.cc,v $
+ * Revision 1.25  2003/04/03 04:30:00  steve
+ *  Prevent overrun comparing verinums to zero.
+ *
  * Revision 1.24  2003/03/25 04:04:29  steve
  *  Handle defaults in synthesized case statements.
  *
diff --git a/verinum.cc b/verinum.cc
index b51b24888..19e7b6ab5 100644
--- a/verinum.cc
+++ b/verinum.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: verinum.cc,v 1.37 2003/02/02 00:43:16 steve Exp $"
+#ident "$Id: verinum.cc,v 1.38 2003/04/03 04:30:00 steve Exp $"
 #endif
 
 # include "config.h"
@@ -293,6 +293,14 @@ bool verinum::is_defined() const
       return true;
 }
 
+bool verinum::is_zero() const
+{
+      for (unsigned idx = 0 ;  idx < nbits_ ;  idx += 1)
+	    if (bits_[idx] != V0) return false;
+
+      return true;
+}
+
 /*
  * This function returns a version of the verinum that has only as
  * many bits as are needed to accurately represent the value. It takes
@@ -818,6 +826,9 @@ verinum::V operator & (verinum::V l, verinum::V r)
 
 /*
  * $Log: verinum.cc,v $
+ * Revision 1.38  2003/04/03 04:30:00  steve
+ *  Prevent overrun comparing verinums to zero.
+ *
  * Revision 1.37  2003/02/02 00:43:16  steve
  *  Fix conversion of signed numbes to long
  *
diff --git a/verinum.h b/verinum.h
index 88f020a53..5c40c9036 100644
--- a/verinum.h
+++ b/verinum.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: verinum.h,v 1.22 2003/01/30 16:23:08 steve Exp $"
+#ident "$Id: verinum.h,v 1.23 2003/04/03 04:30:00 steve Exp $"
 #endif
 
 # include  <string>
@@ -71,6 +71,7 @@ class verinum {
 
 	// A number is "defined" if there are no x or z bits in its value.
       bool is_defined() const;
+      bool is_zero() const;
 
 	// A number is "a string" if its value came directly from
 	// an ASCII description instead of a number value.
@@ -131,6 +132,9 @@ extern verinum v_not(const verinum&left);
 
 /*
  * $Log: verinum.h,v $
+ * Revision 1.23  2003/04/03 04:30:00  steve
+ *  Prevent overrun comparing verinums to zero.
+ *
  * Revision 1.22  2003/01/30 16:23:08  steve
  *  Spelling fixes.
  *