diff --git a/utils/tply/lexbase.pas b/utils/tply/lexbase.pas
index f6b329203c..719df5f2ee 100644
--- a/utils/tply/lexbase.pas
+++ b/utils/tply/lexbase.pas
@@ -969,7 +969,7 @@ function path(filename : String) : String;
   var i : Integer;
   begin
     i := length(filename);
-    while (i>0) and (filename[i]<>'\') and (filename[i]<>':') do
+    while (i>0) and (filename[i]<>DirectorySeparator) and (filename[i]<>':') do
       dec(i);
     path := copy(filename, 1, i);
   end(*path*);
@@ -985,10 +985,10 @@ function root(filename : String) : String;
             root := copy(filename, 1, i-1);
             exit
           end;
-        '\': exit;
+        DirectorySeparator : exit;
         else
       end;
-  end(*addExt*);
+  end(*root*);
 function addExt(filename, ext : String) : String;
   (* implemented with goto for maximum efficiency *)
   label x;
@@ -999,7 +999,7 @@ function addExt(filename, ext : String) : String;
     for i := length(filename) downto 1 do
       case filename[i] of
         '.' : exit;
-        '\': goto x;
+        DirectorySeparator: goto x;
         else
       end;
     x : addExt := filename+'.'+ext
diff --git a/utils/tply/plex.pas b/utils/tply/plex.pas
index df2aefd1d3..9ea37b962f 100644
--- a/utils/tply/plex.pas
+++ b/utils/tply/plex.pas
@@ -597,7 +597,11 @@ var i : Integer;
 
 begin
 {$ifdef Unix}
-  codfilepath1:='/usr/local/lib/fpc/lexyacc/';
+  codfilepath1:=path(paramstr(0));
+  if (codfilepath1<>'') then
+    codfilepath1:=codfilepath1+'../lib/fpc/lexyacc/'
+  else
+    codfilepath1:='/usr/local/lib/fpc/lexyacc/';
   codfilepath2:='/usr/lib/fpc/lexyacc/';
 {$else}
   codfilepath1:=path(paramstr(0));
diff --git a/utils/tply/pyacc.pas b/utils/tply/pyacc.pas
index 7964476f6e..530ff7842e 100644
--- a/utils/tply/pyacc.pas
+++ b/utils/tply/pyacc.pas
@@ -2375,7 +2375,11 @@ var i : Integer;
 
 begin
 {$ifdef Unix}
-  codfilepath1:='/usr/local/lib/fpc/lexyacc/';
+  codfilepath1:=path(paramstr(0));
+  if (codfilepath1<>'') then
+    codfilepath1:=codfilepath1+'../lib/fpc/lexyacc/'
+  else
+    codfilepath1:='/usr/local/lib/fpc/lexyacc/';
   codfilepath2:='/usr/lib/fpc/lexyacc/';
 {$else}
   codfilepath1:=path(paramstr(0));
diff --git a/utils/tply/pyacc.y b/utils/tply/pyacc.y
index ddf614e1ce..5817810d8f 100644
--- a/utils/tply/pyacc.y
+++ b/utils/tply/pyacc.y
@@ -711,7 +711,11 @@ var i : Integer;
 
 begin
 {$ifdef Unix}
-  codfilepath1:='/usr/local/lib/fpc/lexyacc/';
+  codfilepath1:=path(paramstr(0));
+  if (codfilepath1<>'') then
+    codfilepath1:=codfilepath1+'../lib/fpc/lexyacc/'
+  else
+    codfilepath1:='/usr/local/lib/fpc/lexyacc/';
   codfilepath2:='/usr/lib/fpc/lexyacc/';
 {$else}
   codfilepath1:=path(paramstr(0));
diff --git a/utils/tply/yaccbase.pas b/utils/tply/yaccbase.pas
index d48188d016..d161ed8be9 100644
--- a/utils/tply/yaccbase.pas
+++ b/utils/tply/yaccbase.pas
@@ -640,7 +640,7 @@ function path(filename : String) : String;
   var i : Integer;
   begin
     i := length(filename);
-    while (i>0) and (filename[i]<>'\') and (filename[i]<>':') do
+    while (i>0) and (filename[i]<>DirectorySeparator) and (filename[i]<>':') do
       dec(i);
     path := copy(filename, 1, i);
   end(*path*);
@@ -656,10 +656,10 @@ function root(filename : String) : String;
             root := copy(filename, 1, i-1);
             exit
           end;
-        '\': exit;
+        DirectorySeparator: exit;
         else
       end;
-  end(*addExt*);
+  end(*root*);
 function addExt(filename, ext : String) : String;
   (* implemented with goto for maximum efficiency *)
   label x;
@@ -670,7 +670,7 @@ function addExt(filename, ext : String) : String;
     for i := length(filename) downto 1 do
       case filename[i] of
         '.' : exit;
-        '\': goto x;
+        DirectorySeparator : goto x;
         else
       end;
     x : addExt := filename+'.'+ext