diff --git a/compiler/dbgdwarf.pas b/compiler/dbgdwarf.pas
index 1d6ec8bfb0..a9bddb8241 100644
--- a/compiler/dbgdwarf.pas
+++ b/compiler/dbgdwarf.pas
@@ -3264,7 +3264,7 @@ implementation
         ditem : TDirIndexItem;
         fitem : TFileIndexItem;
         flist : TFPList;
-        dbgname : String;
+        dbgname : TSymStr;
       begin
         if not (target_info.system in systems_wasm) then
           begin
diff --git a/compiler/ncgvmt.pas b/compiler/ncgvmt.pas
index 6fb44f4253..03c34bbe23 100644
--- a/compiler/ncgvmt.pas
+++ b/compiler/ncgvmt.pas
@@ -695,11 +695,11 @@ implementation
            Interface tables
 **************************************}
 
-    function CreateWrapperName(_class : tobjectdef;AImplIntf : TImplementedInterface;i : longint;pd : tprocdef) : string;
+    function CreateWrapperName(_class : tobjectdef;AImplIntf : TImplementedInterface;i : longint;pd : tprocdef) : TSymStr;
       var
         realintfdef: tobjectdef;
         tmpstr : AnsiString;
-        hs : string;
+        hs : TSymStr;
         crc : DWord;
       begin
         realintfdef:=AImplIntf.IntfDef;
diff --git a/compiler/ngenutil.pas b/compiler/ngenutil.pas
index d3e26f3b94..0eb1366d9e 100644
--- a/compiler/ngenutil.pas
+++ b/compiler/ngenutil.pas
@@ -1282,7 +1282,7 @@ implementation
 
   class procedure tnodeutils.InsertThreadvars;
     var
-      s : string;
+      s : TSymStr;
       tcb: ttai_typedconstbuilder;
       sym: tasmsymbol;
       tabledef: trecorddef;
diff --git a/compiler/pdecobj.pas b/compiler/pdecobj.pas
index 0fff0a20c9..5636b4da5b 100644
--- a/compiler/pdecobj.pas
+++ b/compiler/pdecobj.pas
@@ -1441,7 +1441,7 @@ implementation
         old_current_specializedef: tstoreddef;
         old_parse_generic: boolean;
         list: TFPObjectList;
-        s: String;
+        s: TSymStr;
         st: TSymtable;
         olddef: tdef;
       begin
diff --git a/compiler/pmodules.pas b/compiler/pmodules.pas
index fefb3d6e04..dbf089126d 100644
--- a/compiler/pmodules.pas
+++ b/compiler/pmodules.pas
@@ -679,7 +679,7 @@ implementation
       end;
 
 
-    function create_main_proc(const name:string;potype:tproctypeoption;st:TSymtable):tcgprocinfo;
+    function create_main_proc(const name:TSymStr;potype:tproctypeoption;st:TSymtable):tcgprocinfo;
       var
         ps  : tprocsym;
         pd  : tprocdef;
diff --git a/compiler/symdef.pas b/compiler/symdef.pas
index b032b77dbe..6a48d9b774 100644
--- a/compiler/symdef.pas
+++ b/compiler/symdef.pas
@@ -1689,11 +1689,11 @@ implementation
 
     procedure tdefawaresymtablestack.add_helpers_and_generics(st:tsymtable;addgenerics:boolean);
       var
-        i: integer;
-        s: string;
+        s: TSymStr;
         list: TFPObjectList;
         def: tdef;
         sym : tsym;
+        i: integer;
       begin
         { search the symtable from first to last; the helper to use will be the
           last one in the list }
diff --git a/compiler/symtable.pas b/compiler/symtable.pas
index cf9ce737de..ff29e0856d 100644
--- a/compiler/symtable.pas
+++ b/compiler/symtable.pas
@@ -324,7 +324,7 @@ interface
     function  FullTypeName(def,otherdef:tdef):string;
     function generate_nested_name(symtable:tsymtable;const delimiter:string):string;
     { def is the extended type of a helper }
-    function generate_objectpascal_helper_key(def:tdef):string;
+    function generate_objectpascal_helper_key(def:tdef):TSymStr;
     procedure incompatibletypes(def1,def2:tdef);
     procedure hidesym(sym:TSymEntry);
     procedure duplicatesym(var hashedid: THashedIDString; dupsym, origsym:TSymEntry; warn: boolean);
@@ -2950,7 +2950,7 @@ implementation
       end;
 
 
-    function generate_objectpascal_helper_key(def:tdef):string;
+    function generate_objectpascal_helper_key(def:tdef):TSymStr;
       begin
         if not assigned(def) then
           internalerror(2013020501);
@@ -4303,7 +4303,7 @@ implementation
 
     function get_objectpascal_helpers(pd : tdef):TFPObjectList;
       var
-        s : string;
+        s : TSymStr;
         st : tsymtable;
       begin
         result:=nil;