diff --git a/Changes b/Changes
index 9cd7d5638..02aefa713 100644
--- a/Changes
+++ b/Changes
@@ -5,6 +5,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 * Verilator 3.877 devel
 
+****  Fix very long module names, bug937. [Todd Strader]
+
 ****  Fix internal error on dotted refs into generates, bug958. [Jie Xu]
 
 ****  Fix mis-optimizing public DPI functions, bug963. [Wei Song]
diff --git a/src/V3Ast.cpp b/src/V3Ast.cpp
index 8b577113a..65786faaa 100644
--- a/src/V3Ast.cpp
+++ b/src/V3Ast.cpp
@@ -28,6 +28,7 @@
 #include "V3File.h"
 #include "V3Global.h"
 #include "V3Broken.h"
+#include "V3String.h"
 
 //======================================================================
 // Statics
@@ -115,6 +116,10 @@ string AstNode::encodeName(const string& namein) {
 	    out += hex;
 	}
     }
+    // Shorten names
+    // TODO long term use VName in place of "string name"
+    VName vname(out);
+    out = vname.hashedName();
     return out;
 }
 
diff --git a/src/V3Options.cpp b/src/V3Options.cpp
index 8570953b8..edcd57786 100644
--- a/src/V3Options.cpp
+++ b/src/V3Options.cpp
@@ -711,6 +711,10 @@ void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc, char
 		shift;
 		addCFlags(argv[i]);
 	    }
+	    else if ( !strcmp (sw, "-comp-limits-syms") && (i+1)<argc ) {  // Undocumented
+		shift;
+		VName::maxLength(atoi(argv[i]));
+	    }
 	    else if ( !strcmp (sw, "-converge-limit") && (i+1)<argc ) {
 		shift;
 		m_convergeLimit = atoi(argv[i]);
@@ -1190,6 +1194,8 @@ V3Options::V3Options() {
 
     m_defaultLanguage = V3LangCode::mostRecent();
 
+    VName::maxLength(128); // Linux filename limits 256; leave half for prefix
+
     optimize(true);
     // Default +libext+
     addLibExtV("");  // So include "filename.v" will find the same file
diff --git a/src/V3Param.cpp b/src/V3Param.cpp
index ee06aea77..d5b42f934 100644
--- a/src/V3Param.cpp
+++ b/src/V3Param.cpp
@@ -470,6 +470,7 @@ void ParamVisitor::visitCell(AstCell* nodep) {
 	} else {
 	    // If the name is very long, we don't want to overwhelm the filename limit
 	    // We don't do this always, as it aids debugability to have intuitive naming.
+	    // TODO can use new V3Name hash replacement instead of this
 	    string newname = longname;
 	    if (longname.length()>30) {
 		LongMap::iterator iter = m_longMap.find(longname);
diff --git a/src/V3String.cpp b/src/V3String.cpp
index fa417195e..151849bc2 100644
--- a/src/V3String.cpp
+++ b/src/V3String.cpp
@@ -21,9 +21,14 @@
 #include "config_build.h"
 #include "verilatedos.h"
 
+#include "V3Global.h"
 #include "V3String.h"
 #include "V3Error.h"
 
+
+size_t VName::s_minLength = 32;
+size_t VName::s_maxLength = 0;	// Disabled
+
 //######################################################################
 // Wildcard
 
@@ -282,3 +287,24 @@ void VHashSha1::selfTest() {
 		"9026e8faed6ef4ec5ae3ff049020d7f0af7abbbf",
 		"kCboAu1u9Oxa4B8EkCDX8K96u78");
 }
+
+//######################################################################
+// VName
+
+string VName::hashedName() {
+    if (m_name=="") return "";
+    if (m_hashed!="") return m_hashed; // Memoized
+    if (s_maxLength==0 || m_name.length() < s_maxLength) {
+	m_hashed = m_name;
+	return m_hashed;
+    } else {
+	VHashSha1 hash(m_name);
+	string suffix = "__Vhsh"+hash.digestSymbol();
+	if (s_minLength < s_maxLength) {
+	    m_hashed = m_name.substr(0,s_minLength) + suffix;
+	} else {
+	    m_hashed = suffix;
+	}
+	return m_hashed;
+    }
+}
diff --git a/src/V3String.h b/src/V3String.h
index 1cf35abab..99c256e58 100644
--- a/src/V3String.h
+++ b/src/V3String.h
@@ -56,8 +56,8 @@ public:
     VHashSha1() { init(); }
     VHashSha1(const string& data) { init(); insert(data); }
     ~VHashSha1() {}
+
     // METHODS
-   
     string digestBinary();		// Return digest as 20 character binary
     string digestHex();			// Return digest formatted as a hex string
     string digestSymbol();		// Return digest formatted as C symbol/base64ish
@@ -81,6 +81,29 @@ private:
     void finalize();			// Process remaining data
 };
 
+//######################################################################
+// VName - string which contains a possibly hashed string
+// TODO use this wherever there is currently a "string m_name"
+
+class VName {
+    string m_name;
+    string m_hashed;
+
+    static size_t s_maxLength;		// Length at which to start hashing
+    static size_t s_minLength;		// Length to preserve if over maxLength
+public:
+    // CONSTRUCTORS
+    VName (const string& name) : m_name(name) {}
+    ~VName() {}
+    // METHODS
+    void name(const string& name) { m_name = name; m_hashed = ""; }
+    string name() const { return m_name; }
+    string hashedName();
+    // CONFIG STATIC METHORS
+    static void maxLength(size_t flag) { s_maxLength=flag; } // Length at which to start hashing, 0=disable
+    static size_t maxLength() { return s_maxLength; }
+};
+
 //######################################################################
 
 #endif // guard
diff --git a/test_regress/t/t_mod_longname.pl b/test_regress/t/t_mod_longname.pl
new file mode 100755
index 000000000..f91289753
--- /dev/null
+++ b/test_regress/t/t_mod_longname.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/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.
+
+compile (
+    );
+
+execute (
+    check_finished=>1,
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_mod_longname.v b/test_regress/t/t_mod_longname.v
new file mode 100644
index 000000000..8198fda02
--- /dev/null
+++ b/test_regress/t/t_mod_longname.v
@@ -0,0 +1,30 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// The code as shown makes a really big file name with Verilator.
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2015 by Todd Strader.
+
+`define LONG_NAME_MOD modlongnameiuqyrewewriqyewroiquyweriuqyewriuyewrioryqoiewyriuewyrqrqioeyriuqyewriuqyeworqiurewyqoiuewyrqiuewoyewriuoeyqiuewryqiuewyroiqyewiuryqeiuwryuqiyreoiqyewiuryqewiruyqiuewyroiuqyewroiuyqewoiryqiewuyrqiuewyroqiyewriuqyewrewqroiuyqiuewyriuqyewroiqyewroiquewyriuqyewroiqewyriuqewyroiqyewroiyewoiuryqoiewyriuqyewiuryqoierwyqoiuewyrewoiuyqroiewuryewurqyoiweyrqiuewyreqwroiyweroiuyqweoiuryqiuewyroiuqyroie
+`define LONG_NAME_SUB sublongnameiuqyrewewriqyewroiquyweriuqyewriuyewrioryqoiewyriuewyrqrqioeyriuqyewriuqyeworqiurewyqoiuewyrqiuewoyewriuoeyqiuewryqiuewyroiqyewiuryqeiuwryuqiyreoiqyewiuryqewiruyqiuewyroiuqyewroiuyqewoiryqiewuyrqiuewyroqiyewriuqyewrewqroiuyqiuewyriuqyewroiqyewroiquewyriuqyewroiqewyriuqewyroiqyewroiyewoiuryqoiewyriuqyewiuryqoierwyqoiuewyrewoiuyqroiewuryewurqyoiweyrqiuewyreqwroiyweroiuyqweoiuryqiuewyroiuqyroie
+`define LONG_NAME_VAR varlongnameiuqyrewewriqyewroiquyweriuqyewriuyewrioryqoiewyriuewyrqrqioeyriuqyewriuqyeworqiurewyqoiuewyrqiuewoyewriuoeyqiuewryqiuewyroiqyewiuryqeiuwryuqiyreoiqyewiuryqewiruyqiuewyroiuqyewroiuyqewoiryqiewuyrqiuewyroqiyewriuqyewrewqroiuyqiuewyriuqyewroiqyewroiquewyriuqyewroiqewyriuqewyroiqyewroiyewoiuryqoiewyriuqyewiuryqoierwyqoiuewyrewoiuyqroiewuryewurqyoiweyrqiuewyreqwroiyweroiuyqweoiuryqiuewyroiuqyroie
+
+module t ();
+
+   initial begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+   logic `LONG_NAME_VAR;
+
+   `LONG_NAME_MOD
+     `LONG_NAME_SUB
+       ();
+
+endmodule
+
+module `LONG_NAME_MOD ();
+   // Force Verilator to make a new class
+   logic a1 /* verilator public */;
+endmodule