diff --git a/vpi/sys_lxt.c b/vpi/sys_lxt.c
index 1db04ccf7..c87ee4d58 100644
--- a/vpi/sys_lxt.c
+++ b/vpi/sys_lxt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002-2009 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2002-2010 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -730,13 +730,13 @@ static PLI_INT32 sys_dumpvars_calltf(PLI_BYTE8*name)
       if (dump_file == 0) {
 	    open_dumpfile(callh);
 	    if (dump_file == 0) {
-		  vpi_free_object(argv);
+		  if (argv) vpi_free_object(argv);
 		  return 0;
 	    }
       }
 
       if (install_dumpvars_callback()) {
-	    vpi_free_object(argv);
+	    if (argv) vpi_free_object(argv);
 	    return 0;
       }
 
diff --git a/vpi/sys_lxt2.c b/vpi/sys_lxt2.c
index 511accba1..243f386c0 100644
--- a/vpi/sys_lxt2.c
+++ b/vpi/sys_lxt2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003-2009 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2003-2010 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -741,13 +741,13 @@ static PLI_INT32 sys_dumpvars_calltf(PLI_BYTE8*name)
       if (dump_file == 0) {
 	    open_dumpfile(callh);
 	    if (dump_file == 0) {
-		  vpi_free_object(argv);
+		  if (argv) vpi_free_object(argv);
 		  return 0;
 	    }
       }
 
       if (install_dumpvars_callback()) {
-	    vpi_free_object(argv);
+	    if (argv) vpi_free_object(argv);
 	    return 0;
       }
 
diff --git a/vpi/sys_vcd.c b/vpi/sys_vcd.c
index 10465c668..18f2a5fe9 100644
--- a/vpi/sys_vcd.c
+++ b/vpi/sys_vcd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2009 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1999-2010 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -755,13 +755,13 @@ static PLI_INT32 sys_dumpvars_calltf(PLI_BYTE8*name)
       if (dump_file == 0) {
 	    open_dumpfile(callh);
 	    if (dump_file == 0) {
-		  vpi_free_object(argv);
+		  if (argv) vpi_free_object(argv);
 		  return 0;
 	    }
       }
 
       if (install_dumpvars_callback()) {
-	    vpi_free_object(argv);
+	    if (argv) vpi_free_object(argv);
 	    return 0;
       }