diff --git a/Changes b/Changes
index 4e970017b..164c29498 100644
--- a/Changes
+++ b/Changes
@@ -3,6 +3,10 @@ Revision history for Verilator
 The contributors that suggested a given feature are shown in [].  [by ...]
 indicates the contributor was also the author of the fix; Thanks!
 
+* Verilator 3.80***
+
+***  Add -F option to read relative option files, bug297. [Neil Hamilton]
+
 * Verilator 3.805 2010/11/02
 
 **** Add warning when directory contains spaces, msg378.  [Salman Sheikh]
diff --git a/bin/verilator b/bin/verilator
index cdecb91b5..96e78107b 100755
--- a/bin/verilator
+++ b/bin/verilator
@@ -227,6 +227,7 @@ descriptions in the next sections for more information.
      -E                          Preprocess, but do not compile
     --error-limit <value>       Abort after this number of errors
     --exe                       Link to create executable
+     -F <file>                  Parse options from a file, relatively
      -f <file>                  Parse options from a file
     --help                      Display this help.
      -I<dir>                    Directory to search for includes
@@ -502,10 +503,18 @@ After this number of errors or warnings are encountered, exit.  Defaults to
 Generate a executable.  You will also need to pass additional .cpp files on
 the command line that implement the main loop for your simulation.
 
+=item -F I<file>
+
+Read the specified file, and act as if all text inside it was specified as
+command line parameters.  Any relative paths are relative to the directory
+containing the specified file.  Note -F is fairly standard across Verilog
+tools.
+
 =item -f I<file>
 
 Read the specified file, and act as if all text inside it was specified as
-command line parameters.  Note -f is fairly standard across Verilog tools.
+command line parameters.  Any relative paths are relative to the current
+directory.  Note -f is fairly standard across Verilog tools.
 
 =item --help
 
diff --git a/src/V3Options.cpp b/src/V3Options.cpp
index 64f2a3b49..d8f188aa1 100644
--- a/src/V3Options.cpp
+++ b/src/V3Options.cpp
@@ -213,6 +213,10 @@ string V3Options::filenameSubstitute (const string& filename) {
     return out;
 }
 
+bool V3Options::filenameIsRel(const string& filename) {
+    return (filename.length()>0 && filename[0] != '/');
+}
+
 bool V3Options::fileStatDir(const string& filename) {
     struct stat	m_stat;		// Stat information
     int err = stat(filename.c_str(), &m_stat);
@@ -520,7 +524,7 @@ string V3Options::argString (int argc, char** argv) {
 void V3Options::parseOpts (FileLine* fl, int argc, char** argv) {
     // Parse all options
     // Inital entry point from Verilator.cpp
-    parseOptsList (fl, argc, argv);
+    parseOptsList (fl, ".", argc, argv);
 
     // Default certain options and error check
     // Detailed error, since this is what we often get when run with minimal arguments
@@ -556,7 +560,7 @@ bool V3Options::suffixed(const char* sw, const char* arg) {
     return (0==strcmp(sw+strlen(sw)-strlen(arg), arg));
 }
 
-void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
+void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc, char** argv) {
     // Parse parameters
     // Note argc and argv DO NOT INCLUDE the filename in [0]!!!
     // May be called recursively when there are -f files.
@@ -572,7 +576,7 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 		addDefine (string (sw+strlen("+define+")));
 	    }
 	    else if ( !strncmp (sw, "+incdir+", 8)) {
-		addIncDir (filenameSubstitute(string (sw+strlen("+incdir+"))));
+		addIncDir (parseFileArg(optdir, string (sw+strlen("+incdir+"))));
 	    }
 	    else if ( !strncmp (sw, "+libext+", 8)) {
 		string exts = string(sw+strlen("+libext+"));
@@ -694,7 +698,7 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 		m_errorLimit = atoi(argv[i]);
 	    }
 	    else if ( !strncmp (sw, "-I", 2)) {
-		addIncDir (string (sw+strlen("-I")));
+		addIncDir (parseFileArg(optdir, string (sw+strlen("-I"))));
 	    }
 	    else if ( !strcmp (sw, "-inline-mult") && (i+1)<argc ) {
 		shift;
@@ -753,7 +757,7 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 	    }
 	    else if ( !strcmp (sw, "-v") && (i+1)<argc ) {
 		shift;
-		V3Options::addLibraryFile(filenameSubstitute(argv[i]));
+		V3Options::addLibraryFile(parseFileArg(optdir,argv[i]));
 	    }
 	    else if ( !strcmp (sw, "-V") ) {
 		showVersion(true);
@@ -815,9 +819,13 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 		    fl->v3fatal("Unknown setting for --compiler: "<<argv[i]);
 		}
 	    }
+	    else if ( !strcmp (sw, "-F") && (i+1)<argc ) {
+		shift;
+		parseOptsFile(fl, parseFileArg(optdir,argv[i]), true);
+	    }
 	    else if ( !strcmp (sw, "-f") && (i+1)<argc ) {
 		shift;
-		parseOptsFile(fl, filenameSubstitute(argv[i]));
+		parseOptsFile(fl, parseFileArg(optdir,argv[i]), false);
 	    }
 	    else if ( !strcmp (sw, "-gdb") && (i+1)<argc ) {
 		shift; // Used only in perl shell
@@ -852,7 +860,7 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 		}
 	    }
 	    else if ( !strcmp (sw, "-y") && (i+1)<argc ) {
-		shift; addIncDir (string (argv[i]));
+		shift; addIncDir (parseFileArg(optdir,string (argv[i])));
 	    }
 	    else {
 		fl->v3fatal ("Invalid Option: "<<argv[i]);
@@ -861,7 +869,7 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 	} // - options
 	else {
 	    // Filename
-	    string filename = filenameSubstitute(argv[i]);
+	    string filename = parseFileArg(optdir,argv[i]);
 	    if (suffixed(filename.c_str(), ".cpp")
 		|| suffixed(filename.c_str(), ".cxx")
 		|| suffixed(filename.c_str(), ".cc")
@@ -884,7 +892,7 @@ void V3Options::parseOptsList(FileLine* fl, int argc, char** argv) {
 
 //======================================================================
 
-void V3Options::parseOptsFile(FileLine* fl, const string& filename) {
+void V3Options::parseOptsFile(FileLine* fl, const string& filename, bool rel) {
     // Read the specified -f filename and process as arguments
     UINFO(1,"Reading Options File "<<filename<<endl);
 
@@ -946,12 +954,25 @@ void V3Options::parseOptsFile(FileLine* fl, const string& filename) {
 	startpos = endpos;
     }
 
+    // Path
+    string optdir = (rel ? V3Options::filenameDir(filename) : ".");
+
     // Convert to argv style arg list and parse them
     char* argv [args.size()+1];
     for (unsigned i=0; i<args.size(); ++i) {
 	argv[i] = (char*)args[i].c_str();
     }
-    parseOptsList(fl, args.size(), argv);
+    parseOptsList(fl, optdir, args.size(), argv);
+}
+
+//======================================================================
+
+string V3Options::parseFileArg(const string& optdir, const string& relfilename) {
+    string filename = V3Options::filenameSubstitute(relfilename);
+    if (optdir != "." && filenameIsRel(filename)) {
+	filename = optdir + "/" + filename;
+    }
+    return filename;
 }
 
 //======================================================================
diff --git a/src/V3Options.h b/src/V3Options.h
index 09b993cb8..0c1da2e19 100644
--- a/src/V3Options.h
+++ b/src/V3Options.h
@@ -182,6 +182,7 @@ class V3Options {
     void coverage(bool flag) { m_coverageLine = m_coverageToggle = m_coverageUser = flag; }
     bool onoff(const char* sw, const char* arg, bool& flag);
     bool suffixed(const char* sw, const char* arg);
+    string parseFileArg(const string& optdir, const string& relfilename);
 
     static bool wildmatchi(const char* s, const char* p);
     static string getenvStr(const string& envvar, const string& defaultValue);
@@ -301,8 +302,8 @@ class V3Options {
     string allArgsString();	///< Return all passed arguments as simple string
     void bin(const string& flag) { m_bin = flag; }
     void parseOpts(FileLine* fl, int argc, char** argv);
-    void parseOptsList (FileLine* fl, int argc, char** argv);
-    void parseOptsFile (FileLine* fl, const string& filename);
+    void parseOptsList (FileLine* fl, const string& optdir, int argc, char** argv);
+    void parseOptsFile (FileLine* fl, const string& filename, bool rel);
 
     // METHODS (generic string utilities)
     static bool wildmatch(const char* s, const char* p);
@@ -315,6 +316,7 @@ class V3Options {
     static string filenameNonDirExt (const string& filename) { return filenameNonExt(filenameNonDir(filename)); }	///< Return basename of filename
     static string filenameDir (const string& filename);	///< Return directory part of filename
     static string filenameSubstitute (const string& filename);	///< Return filename with env vars removed
+    static bool   filenameIsRel (const string& filename);	///< True if relative
     static void   unlinkRegexp(const string& dir, const string& regexp);
 
     // METHODS (environment)
diff --git a/test_regress/t/t_flag_f.v b/test_regress/t/t_flag_f.v
index 7a0567f11..5532d93da 100644
--- a/test_regress/t/t_flag_f.v
+++ b/test_regress/t/t_flag_f.v
@@ -1,5 +1,7 @@
 // DESCRIPTION: Verilator: Verilog Test module
 
+`include "t_flag_f_tsub_inc.v"
+
 module t;
    initial begin
 `ifndef GOT_DEF1
@@ -11,6 +13,15 @@ module t;
 `ifndef GOT_DEF3
       $write("%%Error: NO GOT_DEF3\n"); $stop;
 `endif
+`ifndef GOT_DEF4
+      $write("%%Error: NO GOT_DEF4\n"); $stop;
+`endif
+`ifndef GOT_DEF5
+      $write("%%Error: NO GOT_DEF5\n"); $stop;
+`endif
+`ifndef GOT_DEF6
+      $write("%%Error: NO GOT_DEF6\n"); $stop;
+`endif
 `ifdef NON_DEF
       $write("%%Error: NON_DEF\n"); $stop;
 `endif
diff --git a/test_regress/t/t_flag_f.vc b/test_regress/t/t_flag_f.vc
index ca57b7f69..887dc4587 100644
--- a/test_regress/t/t_flag_f.vc
+++ b/test_regress/t/t_flag_f.vc
@@ -2,3 +2,5 @@
 -f $VERILATOR_ROOT/test_regress/t/t_flag_f__2.vc
 // Env var with .v file
 $VERILATOR_ROOT/test_regress/t/t_flag_f__3.v
+// Test -f
+-F $VERILATOR_ROOT/test_regress/t/tsub/t_flag_f_tsub.vc
diff --git a/test_regress/t/tsub/t_flag_f_tsub.v b/test_regress/t/tsub/t_flag_f_tsub.v
new file mode 100644
index 000000000..04329e761
--- /dev/null
+++ b/test_regress/t/tsub/t_flag_f_tsub.v
@@ -0,0 +1,3 @@
+// DESCRIPTION: Verilator: Verilog Test module
+
+`define GOT_DEF6
diff --git a/test_regress/t/tsub/t_flag_f_tsub.vc b/test_regress/t/tsub/t_flag_f_tsub.vc
new file mode 100644
index 000000000..aa7e76cf1
--- /dev/null
+++ b/test_regress/t/tsub/t_flag_f_tsub.vc
@@ -0,0 +1,5 @@
+// DESCRIPTION: Verilator: Verilog Test module
+
++define+GOT_DEF4=1
++incdir+.
+t_flag_f_tsub.v
diff --git a/test_regress/t/tsub/t_flag_f_tsub_inc.v b/test_regress/t/tsub/t_flag_f_tsub_inc.v
new file mode 100644
index 000000000..840561da1
--- /dev/null
+++ b/test_regress/t/tsub/t_flag_f_tsub_inc.v
@@ -0,0 +1,3 @@
+// DESCRIPTION: Verilator: Verilog Test module
+
+`define GOT_DEF5