diff --git a/include/verilated_save.cpp b/include/verilated_save.cpp
index e571e9cf8..26d626102 100644
--- a/include/verilated_save.cpp
+++ b/include/verilated_save.cpp
@@ -42,9 +42,10 @@
 // clang-format on
 
 // CONSTANTS
-static const char* const VLTSAVE_HEADER_STR
-    = "verilatorsave01\n";  ///< Value of first bytes of each file
-static const char* const VLTSAVE_TRAILER_STR = "vltsaved";  ///< Value of last bytes of each file
+/// Value of first bytes of each file (must be multiple of 8 bytes)
+static const char* const VLTSAVE_HEADER_STR = "verilatorsave01\n";
+/// Value of last bytes of each file (must be multiple of 8 bytes)
+static const char* const VLTSAVE_TRAILER_STR = "vltsaved";
 
 //=============================================================================
 //=============================================================================
@@ -64,10 +65,10 @@ VerilatedDeserialize& VerilatedDeserialize::readAssert(const void* __restrict da
                                                        size_t size) VL_MT_UNSAFE_ONE {
     if (VL_UNLIKELY(readDiffers(datap, size))) {
         std::string fn = filename();
-        std::string msg
-            = "Can't deserialize save-restore file as was made from different model:" + filename();
+        std::string msg = "Can't deserialize save-restore file as was made from different model: "
+                          + filename();
         VL_FATAL_MT(fn.c_str(), 0, "", msg.c_str());
-        close();
+        // Die before we close() as close would infinite loop
     }
     return *this;  // For function chaining
 }
@@ -88,9 +89,11 @@ void VerilatedDeserialize::header() VL_MT_UNSAFE_ONE {
     if (VL_UNLIKELY(os.readDiffers(VLTSAVE_HEADER_STR, strlen(VLTSAVE_HEADER_STR)))) {
         std::string fn = filename();
         std::string msg
-            = std::string("Can't deserialize; file has wrong header signature: ") + filename();
+            = std::string(
+                  "Can't deserialize; file has wrong header signature, or file not found: ")
+              + filename();
         VL_FATAL_MT(fn.c_str(), 0, "", msg.c_str());
-        close();
+        // Die before we close() as close would infinite loop
     }
     os.read(Verilated::serialized1Ptr(), Verilated::serialized1Size());
     os.read(Verilated::serialized2Ptr(), Verilated::serialized2Size());
@@ -109,7 +112,7 @@ void VerilatedDeserialize::trailer() VL_MT_UNSAFE_ONE {
         std::string msg = std::string("Can't deserialize; file has wrong end-of-file signature: ")
                           + filename();
         VL_FATAL_MT(fn.c_str(), 0, "", msg.c_str());
-        close();
+        // Die before we close() as close would infinite loop
     }
 }
 
diff --git a/test_regress/t/t_savable.v b/test_regress/t/t_savable.v
index 76b18144f..c5e010a4e 100644
--- a/test_regress/t/t_savable.v
+++ b/test_regress/t/t_savable.v
@@ -6,11 +6,17 @@
 
 module t (/*AUTOARG*/
    // Inputs
-   clk
+   clk, model
    );
    /*verilator no_inline_module*/   // So we'll get hiearachy we can test
    input clk;
 
+   // Parameter so we can test for different model error
+   parameter MODEL_WIDTH = 10;
+   input [MODEL_WIDTH-1:0] model;
+
+   initial $write("Model width = %d\n", MODEL_WIDTH);
+
    sub sub (/*AUTOINST*/
 	    // Inputs
 	    .clk			(clk));
diff --git a/test_regress/t/t_savable_format1_bad.out b/test_regress/t/t_savable_format1_bad.out
new file mode 100644
index 000000000..72f5bde4d
--- /dev/null
+++ b/test_regress/t/t_savable_format1_bad.out
@@ -0,0 +1,4 @@
+Model width =         40
+Restoring model from 'obj_vlt/t_savable_format1_bad/saved.vltsv'
+%Error: obj_vlt/t_savable_format1_bad/saved.vltsv:0: Can't deserialize save-restore file as was made from different model: obj_vlt/t_savable_format1_bad/saved.vltsv
+Aborting...
diff --git a/test_regress/t/t_savable_format1_bad.pl b/test_regress/t/t_savable_format1_bad.pl
new file mode 100755
index 000000000..f6ac72e4e
--- /dev/null
+++ b/test_regress/t/t_savable_format1_bad.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(vlt => 1);
+
+top_filename("t/t_savable.v");
+
+compile(
+    v_flags2 => ["--savable"],
+    save_time => 500,
+    );
+
+execute(
+    check_finished => 0,
+    all_run_flags => ['+save_time=500'],
+    );
+
+-r "$Self->{obj_dir}/saved.vltsv" or error("Saved.vltsv not created\n");
+
+compile(
+    v_flags2 => ["--savable -GMODEL_WIDTH=40"],
+    save_time => 500,
+    );
+
+execute(
+    all_run_flags => ['+save_restore=1'],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_savable_format2_bad.out b/test_regress/t/t_savable_format2_bad.out
new file mode 100644
index 000000000..69680ca5b
--- /dev/null
+++ b/test_regress/t/t_savable_format2_bad.out
@@ -0,0 +1,4 @@
+Model width =          10
+Restoring model from 'obj_vlt/t_savable_format2_bad/saved.vltsv'
+%Error: obj_vlt/t_savable_format2_bad/saved.vltsv:0: Can't deserialize; file has wrong header signature, or file not found: obj_vlt/t_savable_format2_bad/saved.vltsv
+Aborting...
diff --git a/test_regress/t/t_savable_format2_bad.pl b/test_regress/t/t_savable_format2_bad.pl
new file mode 100755
index 000000000..c87d9cc87
--- /dev/null
+++ b/test_regress/t/t_savable_format2_bad.pl
@@ -0,0 +1,37 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(vlt => 1);
+
+top_filename("t/t_savable.v");
+
+compile(
+    v_flags2 => ["--savable"],
+    save_time => 500,
+    );
+
+execute(
+    check_finished => 0,
+    all_run_flags => ['+save_time=500'],
+    );
+
+-r "$Self->{obj_dir}/saved.vltsv" or error("Saved.vltsv not created\n");
+
+# Break the header
+run(cmd => ["sed -i.bak 's/verilatorsave01/verilatorsavBAD/' $Self->{obj_dir}/saved.vltsv"]);
+
+execute(
+    all_run_flags => ['+save_restore=1'],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_savable_format3_bad.out b/test_regress/t/t_savable_format3_bad.out
new file mode 100644
index 000000000..3389dee4b
--- /dev/null
+++ b/test_regress/t/t_savable_format3_bad.out
@@ -0,0 +1,4 @@
+Model width =          10
+Restoring model from 'obj_vlt/t_savable_format3_bad/saved.vltsv'
+%Error: obj_vlt/t_savable_format3_bad/saved.vltsv:0: Can't deserialize; file has wrong end-of-file signature: obj_vlt/t_savable_format3_bad/saved.vltsv
+Aborting...
diff --git a/test_regress/t/t_savable_format3_bad.pl b/test_regress/t/t_savable_format3_bad.pl
new file mode 100755
index 000000000..a0cc865de
--- /dev/null
+++ b/test_regress/t/t_savable_format3_bad.pl
@@ -0,0 +1,37 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(vlt => 1);
+
+top_filename("t/t_savable.v");
+
+compile(
+    v_flags2 => ["--savable"],
+    save_time => 500,
+    );
+
+execute(
+    check_finished => 0,
+    all_run_flags => ['+save_time=500'],
+    );
+
+-r "$Self->{obj_dir}/saved.vltsv" or error("Saved.vltsv not created\n");
+
+# Break the header
+run(cmd => ["sed -i.bak 's/vltsaved/vltNOTed/' $Self->{obj_dir}/saved.vltsv"]);
+
+execute(
+    all_run_flags => ['+save_restore=1'],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_savable_open_bad.out b/test_regress/t/t_savable_open_bad.out
new file mode 100644
index 000000000..ca2151f02
--- /dev/null
+++ b/test_regress/t/t_savable_open_bad.out
@@ -0,0 +1,4 @@
+Model width =          10
+Restoring model from 'obj_vlt/t_savable_open_bad/saved.vltsv'
+%Error: obj_vlt/t_savable_open_bad/saved.vltsv:0: Can't deserialize; file has wrong header signature, or file not found: obj_vlt/t_savable_open_bad/saved.vltsv
+Aborting...
diff --git a/test_regress/t/t_savable_open_bad.pl b/test_regress/t/t_savable_open_bad.pl
new file mode 100755
index 000000000..a2160366f
--- /dev/null
+++ b/test_regress/t/t_savable_open_bad.pl
@@ -0,0 +1,27 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(vlt => 1);
+
+top_filename("t/t_savable.v");
+
+compile(
+    v_flags2 => ["--savable"],
+    save_time => 500,
+    );
+
+execute(
+    all_run_flags => ['+save_restore=1'],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;