diff --git a/driver/main.c b/driver/main.c
index 953262012..932f9b1f0 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -570,6 +570,8 @@ int main(int argc, char **argv)
       }
 
       fprintf(defines_file, "D:__ICARUS__=1\n");
+      if (strcmp(gen_verilog_ams,"verilog-ams") == 0)
+	    fprintf(defines_file, "D:__VAMS_ENABLE__=1\n");
 
 	/* Create another temporary file for passing configuration
 	   information to ivl. */