diff --git a/alliance/src/vbl/src/vbl_bcomp_y.y b/alliance/src/vbl/src/vbl_bcomp_y.y
index 0e55fe95..ffd10cec 100644
--- a/alliance/src/vbl/src/vbl_bcomp_y.y
+++ b/alliance/src/vbl/src/vbl_bcomp_y.y
@@ -48,9 +48,12 @@
 # define my_fprintf fprintf( stdout, "%s %d : ", basename(__FILE__), __LINE__ ); fprintf
 # define my_vbl_error(N,V) \
    do { fprintf( stderr, "%s %d : ", basename(__FILE__), __LINE__); vbl_error(N,V); } while(0)
+# define my_vbl_warning(N,V) \
+   do { fprintf( stderr, "%s %d : ", basename(__FILE__), __LINE__); vbl_warning(N,V); } while(0)
 #else
 # define my_fprintf   fprintf
 # define my_vbl_error vbl_error
+# define my_vbl_warning vbl_warning
 #endif
 
 #ifdef VBL_DEBUG
@@ -6043,9 +6046,28 @@ signal_assignment_statement
        ;
 
 waveform_element
-       : expression
-              { $$ = $1; }
-       ;
+	: expression
+	  .AFTER__delay_expression.
+		{
+		$$ = $1;
+		}
+	;
+
+.AFTER__delay_expression.
+	: /*empty*/
+		{ }
+	| AFTER
+	  delay_expression
+		{ 
+                  my_vbl_warning( 0, "after clauses ignored !" );
+                }
+	;
+
+delay_expression
+	: AbstractLit
+	  time_label
+		{ }
+	;
 
 if_statement
        : IF
diff --git a/alliance/src/vbl/src/vbl_bspec.h b/alliance/src/vbl/src/vbl_bspec.h
index 3e79117f..20903725 100644
--- a/alliance/src/vbl/src/vbl_bspec.h
+++ b/alliance/src/vbl/src/vbl_bspec.h
@@ -88,5 +88,6 @@ extern int                vbl_intSize();
 extern int                vbl_vextonum();
 extern vbtyp_list *vbl_getbasetype();
   extern void               vbl_error();
+  extern void               vbl_warning();
   extern int                vbl_tobin();
 
diff --git a/alliance/src/vbl/src/vbl_util.c b/alliance/src/vbl/src/vbl_util.c
index 96045871..529a46de 100644
--- a/alliance/src/vbl/src/vbl_util.c
+++ b/alliance/src/vbl/src/vbl_util.c
@@ -502,6 +502,9 @@ char *str1;
       break;
     }
 
+   fprintf( stderr, 
+           "Note that errors might also be due to unsupported statements\n" );
+
   if (VBL_ERRFLG > VBL_MXRDFN)
     {
     (void) fprintf (stderr,"Too many errors. Cannot continue further more\n");
@@ -512,6 +515,26 @@ char *str1;
   autexit(1);
 }
 
+void vbl_warning (code,str1)
+
+int   code;
+char *str1;
+
+{
+  (void)fprintf (stderr,"Warning %d line %ld in file %s :",code,VBL_LINNUM, VBL_FILENAME);
+
+  switch (code)
+    {
+    case 0:
+      (void) fprintf (stderr," %s\n", str1);
+      break;
+
+    default:
+      (void) fprintf (stderr, "unknown warning\n");
+      break;
+    }
+}
+
 /* ###--------------------------------------------------------------### */
 /*  function : vbl_y_error						*/
 /* ###--------------------------------------------------------------### */