diff --git a/Rakefile.rb b/Rakefile.rb
index a1d2b2d..a17d227 100644
--- a/Rakefile.rb
+++ b/Rakefile.rb
@@ -3,7 +3,7 @@ require 'hoe'
 $LOAD_PATH.unshift("./ext")
 
 class IGraph
-  VERSION = "0.9.0"
+  VERSION = "0.9.1"
 end
 
 begin 
diff --git a/ext/cIGraph.c b/ext/cIGraph.c
index 774b0f3..9c16aaa 100644
--- a/ext/cIGraph.c
+++ b/ext/cIGraph.c
@@ -164,6 +164,10 @@ VALUE cIGraph_initialize(int argc, VALUE *argv, VALUE self){
 
 }
 
+VALUE cIGraph_unavailable_method(int argc, VALUE *argv, VALUE self){
+	rb_raise(rb_eNoMethodError,"Method not available on OSX");
+}
+
 /* Interface to the iGraph[http://cneurocvs.rmki.kfki.hu/igraph/] library
  * for graph and network computation.
  *
@@ -449,12 +453,20 @@ void Init_igraph(){
 
   rb_define_method(cIGraph_sorting, "topological_sorting", cIGraph_topological_sorting, 1); /* in cIGraph_topological_sort.c */
 
-  #ifdef __APPLE__
-  #else
   /* Functions for reading graphs from files */
   cIGraph_fileread = rb_define_module_under(cIGraph, "FileRead");
   rb_include_module(cIGraph, cIGraph_fileread);  
 
+  #ifdef __APPLE__
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_edgelist", cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_graphml",  cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_ncol",     cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_lgl",      cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_dimacs",   cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_graphdb",  cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_gml",      cIGraph_unavailable_method, -1);
+  rb_define_singleton_method(cIGraph_fileread, "read_graph_pajek",    cIGraph_unavailable_method, -1);
+  #else
   rb_define_singleton_method(cIGraph_fileread, "read_graph_edgelist", cIGraph_read_graph_edgelist, 2); /* in cIGraph_file.c */
   rb_define_singleton_method(cIGraph_fileread, "read_graph_graphml",  cIGraph_read_graph_graphml, 2);  /* in cIGraph_file.c */  
   rb_define_singleton_method(cIGraph_fileread, "read_graph_ncol",     cIGraph_read_graph_ncol, 5);     /* in cIGraph_file.c */ 
@@ -463,11 +475,21 @@ void Init_igraph(){
   rb_define_singleton_method(cIGraph_fileread, "read_graph_graphdb",  cIGraph_read_graph_graphdb, 2);     /* in cIGraph_file.c */ 
   rb_define_singleton_method(cIGraph_fileread, "read_graph_gml",      cIGraph_read_graph_gml,  1);     /* in cIGraph_file.c */ 
   rb_define_singleton_method(cIGraph_fileread, "read_graph_pajek",    cIGraph_read_graph_pajek, 2);    /* in cIGraph_file.c */
-  
+  #endif
+
   /* Functions for writing graphs to files */
   cIGraph_filewrite = rb_define_module_under(cIGraph, "FileWrite");
   rb_include_module(cIGraph, cIGraph_filewrite);
 
+  #ifdef __APPLE__
+  rb_define_method(cIGraph_filewrite, "write_graph_edgelist", cIGraph_unavailable_method, -1);
+  rb_define_method(cIGraph_filewrite, "write_graph_graphml",  cIGraph_unavailable_method, -1);  
+  rb_define_method(cIGraph_filewrite, "write_graph_gml",      cIGraph_unavailable_method, -1);  
+  rb_define_method(cIGraph_filewrite, "write_graph_ncol",     cIGraph_unavailable_method, -1);    
+  rb_define_method(cIGraph_filewrite, "write_graph_lgl",      cIGraph_unavailable_method, -1); 
+  rb_define_method(cIGraph_filewrite, "write_graph_dimacs",   cIGraph_unavailable_method, -1); 
+  rb_define_method(cIGraph_filewrite, "write_graph_pajek",    cIGraph_unavailable_method, -1);
+  #else
   rb_define_method(cIGraph_filewrite, "write_graph_edgelist", cIGraph_write_graph_edgelist, 1);  /* in cIGraph_file.c */
   rb_define_method(cIGraph_filewrite, "write_graph_graphml",  cIGraph_write_graph_graphml,   1); /* in cIGraph_file.c */  
   rb_define_method(cIGraph_filewrite, "write_graph_gml",      cIGraph_write_graph_gml,    1); /* in cIGraph_file.c */  
@@ -534,7 +556,7 @@ void Init_igraph(){
   rb_define_method(cIGraph_community, "community_eb_get_merges", cIGraph_community_eb_get_merges, 1);  /* in cIGraph_community.c */  
   rb_define_method(cIGraph_community, "community_fastgreedy", cIGraph_community_fastgreedy, 0);  /* in cIGraph_community.c */  
 
-  rb_define_const(cIGraph, "VERSION", rb_str_new2("0.9.0"));
+  rb_define_const(cIGraph, "VERSION", rb_str_new2("0.9.1"));
 
   rb_define_const(cIGraph, "EDGEORDER_ID",   INT2NUM(1));
   rb_define_const(cIGraph, "EDGEORDER_FROM", INT2NUM(2));
diff --git a/test/tc_file_read_write.rb b/test/tc_file_read_write.rb
index 772c340..c49d6d4 100644
--- a/test/tc_file_read_write.rb
+++ b/test/tc_file_read_write.rb
@@ -1,10 +1,18 @@
 require 'test/unit'
 require 'igraph'
 require 'stringio'
+require 'rbconfig'
+include Config
 
 class TestGraph < Test::Unit::TestCase
   def test_edgelist_read
     g = nil
+    if CONFIG['host'] =~ /apple/
+      assert_raises(NoMethodError){
+        IGraph::FileRead.read_graph_edgelist(StringIO.new("0 1 2 3"),true)
+      }
+      return
+    end
     assert_nothing_raised{
       g = IGraph::FileRead.read_graph_edgelist(StringIO.new("0 1 2 3"),true)
     }
@@ -16,6 +24,12 @@ class TestGraph < Test::Unit::TestCase
   def test_edgelist_write
     g = IGraph.new([0,1,2,3])
     s = StringIO.new("")
+    if CONFIG['host'] =~ /apple/
+      assert_raises(NoMethodError){
+        g.write_graph_edgelist(s)
+      }
+      return
+    end
     str = g.write_graph_edgelist(s)
     s.rewind
     assert_equal "0 1\n2 3\n", s.read
@@ -23,9 +37,16 @@ class TestGraph < Test::Unit::TestCase
 
   def test_ncol_read
     g = nil
+    if CONFIG['host'] =~ /apple/
+      assert_raises(NoMethodError){
+        IGraph::FileRead.read_graph_ncol(StringIO.new("0 1\n2 3\n"),[],
+  				  false,false,false)
+      }
+      return
+    end
     assert_nothing_raised{
       g = IGraph::FileRead.read_graph_ncol(StringIO.new("0 1\n2 3\n"),[],
-				 false,false,false)
+				  false,false,false)
     }
     assert_instance_of IGraph, g
     assert_equal 4, g.vcount
@@ -33,7 +54,7 @@ class TestGraph < Test::Unit::TestCase
 
     assert_nothing_raised{
       g = IGraph::FileRead.read_graph_ncol(StringIO.new("A B\nC D\n"),[],
-				 true,false,false)
+				  true,false,false)
     }
     assert_instance_of IGraph, g
     assert_equal 4, g.vcount
@@ -52,6 +73,12 @@ class TestGraph < Test::Unit::TestCase
   def test_ncol_write
     g = IGraph.new(["A","B","C","D"],true,[1,2])
     s = StringIO.new("")
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         g.write_graph_ncol(s,true,true)
+       }
+       return
+    end
     str = g.write_graph_ncol(s,true,true)
     s.rewind
     assert_equal "A B 1.0\nC D 2.0\n", s.read
@@ -59,6 +86,12 @@ class TestGraph < Test::Unit::TestCase
 
   def test_lgl_read
     g = nil
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         IGraph::FileRead.read_graph_lgl(StringIO.new("#A\nB\n#C\nD\n"))
+       }
+       return
+    end
     assert_nothing_raised{
       g = IGraph::FileRead.read_graph_lgl(StringIO.new("#A\nB\n#C\nD\n"),
 				 false,false)
@@ -80,15 +113,27 @@ class TestGraph < Test::Unit::TestCase
   def test_lgl_write
     g = IGraph.new(["A","B","C","D"],true,[1,2])
     s = StringIO.new("")
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         g.write_graph_lgl(s,true,true,false)
+       }
+       return
+    end
     str = g.write_graph_lgl(s,true,true,false)
     s.rewind
     assert_equal "# A\nB 1.0\n# C\nD 2.0\n", s.read
   end
 
   def test_dimacs_read
+    s = StringIO.new("c com\np min 4 2\nn 1 s\nn 2 t\na 1 2 1\na 3 4 2\n")
     g = nil
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         IGraph::FileRead.read_graph_dimacs(s,false)
+       }
+       return
+    end
     assert_nothing_raised{
-      s = StringIO.new("c com\np min 4 2\nn 1 s\nn 2 t\na 1 2 1\na 3 4 2\n")
       g = IGraph::FileRead.read_graph_dimacs(s,
 				   false)
     }
@@ -103,12 +148,24 @@ class TestGraph < Test::Unit::TestCase
   def test_dimacs_write
     g = IGraph.new(["A","B","C","D"],true,[1,2])
     s = StringIO.new("")
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         g.write_graph_dimacs(s,0,1,[1,2])
+       }
+       return
+    end
     str = g.write_graph_dimacs(s,0,1,[1,2])
     s.rewind
     assert_equal "c created by igraph\np max 4 2\nn 1 s\nn 2 t\na 1 2 1\na 3 4 2\n", s.read
   end
 
   def test_graphml_read
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         IGraph::FileRead.read_graph_graphml(StringIO.new(Graphml),0)
+       }
+       return
+    end
     g = nil
     g = IGraph::FileRead.read_graph_graphml(StringIO.new(Graphml),0)
     assert_instance_of IGraph, g
@@ -128,12 +185,24 @@ class TestGraph < Test::Unit::TestCase
                     {'eid'=>'e2'}])
     g.attributes['date'] = 'Friday'
     s = StringIO.new("")
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         g.write_graph_graphml(s)
+       }
+       return
+    end
     str = g.write_graph_graphml(s)
     s.rewind
     assert_equal Graphml_out, s.read
   end
 
   def test_gml_read
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         IGraph::FileRead.read_graph_gml(StringIO.new(Gml))
+       }
+       return
+    end
     g = IGraph::FileRead.read_graph_gml(StringIO.new(Gml))
     assert_instance_of IGraph, g
   end
@@ -148,6 +217,12 @@ class TestGraph < Test::Unit::TestCase
                     {'eid'=>'e2'}])
     g.attributes['date'] = 'Friday'
     s = StringIO.new("")
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         g.write_graph_gml(s)
+       }
+       return
+    end
     str = g.write_graph_gml(s)
     s.rewind
     s = s.read
@@ -156,6 +231,12 @@ class TestGraph < Test::Unit::TestCase
   end
 
   def test_pajek_read_write
+    if CONFIG['host'] =~ /apple/
+       assert_raises(NoMethodError){
+         IGraph::FileRead.read_graph_pajek(StringIO.new(Pajek),0)
+       }
+       return
+    end
     g = nil
     g = IGraph::FileRead.read_graph_pajek(StringIO.new(Pajek),0)
     assert_instance_of IGraph, g
diff --git a/test/test_all.rb b/test/test_all.rb
index 4218cea..d91c57d 100644
--- a/test/test_all.rb
+++ b/test/test_all.rb
@@ -19,11 +19,7 @@ require 'tc_cores'
 require 'tc_dijkstra'
 require 'tc_directedness'
 require 'tc_error_handling'
-
-unless CONFIG['host'] =~ /apple/
-  require 'tc_file_read_write'
-end
-
+require 'tc_file_read_write'
 require 'tc_generators_deterministic'
 require 'tc_generators_random'
 require 'tc_independent_vertex_sets'