diff --git a/components/lazutils/lazutf8.pas b/components/lazutils/lazutf8.pas
index 49d0e20b64..c5c2bfb5c8 100644
--- a/components/lazutils/lazutf8.pas
+++ b/components/lazutils/lazutf8.pas
@@ -54,7 +54,8 @@ function UTF8FindNearestCharStart(UTF8Str: PChar; Len: integer;
 function UTF8CharStart(UTF8Str: PChar; Len, CharIndex: PtrInt): PChar;
 // find the byte index of the n-th UTF8 character, ignoring BIDI (byte len of substr)
 function UTF8CharToByteIndex(UTF8Str: PChar; Len, CharIndex: PtrInt): PtrInt;
-procedure UTF8FixBroken(P: PChar);
+procedure UTF8FixBroken(P: PChar); overload;
+procedure UTF8FixBroken(var S: string); overload;
 function UTF8CharacterStrictLength(P: PChar): integer;
 function UTF8CStringToUTF8String(SourceStart: PChar; SourceLen: PtrInt) : string;
 function UTF8Pos(const SearchForText, SearchInText: string): PtrInt;
@@ -523,7 +524,7 @@ begin
         c:=((ord(p^) and %00011111) shl 6);
            //or (ord(p[1]) and %00111111);
         if c<(1 shl 7) then
-          p^:=' '
+          p^:=' '  // fix XSS attack
         else
           inc(p,2)
       end
@@ -538,7 +539,7 @@ begin
            or ((ord(p[1]) and %00111111) shl 6);
            //or (ord(p[2]) and %00111111);
         if c<(1 shl 11) then
-          p^:=' '
+          p^:=' '  // fix XSS attack
         else
           inc(p,3);
       end else
@@ -554,7 +555,7 @@ begin
            or ((ord(p[2]) and %00111111) shl 6);
            //or (ord(p[3]) and %00111111);
         if c<(1 shl 16) then
-          p^:=' '
+          p^:=' ' // fix XSS attack
         else
           inc(p,4)
       end else
@@ -567,6 +568,14 @@ begin
   end;
 end;
 
+procedure UTF8FixBroken(var S: string);
+begin
+  if S='' then exit;
+  if FindInvalidUTF8Character(PChar(S),length(S),true)<0 then exit;
+  UniqueString(S);
+  UTF8FixBroken(PChar(S));
+end;
+
 function UTF8CharacterStrictLength(P: PChar): integer;
 begin
   if p=nil then exit(0);
diff --git a/components/wiki/lazwiki/wikiparser.pas b/components/wiki/lazwiki/wikiparser.pas
index f4a8449bc2..65fde5165f 100644
--- a/components/wiki/lazwiki/wikiparser.pas
+++ b/components/wiki/lazwiki/wikiparser.pas
@@ -1499,18 +1499,8 @@ begin
 end;
 
 procedure TWikiPage.FixUTF8;
-var
-  p: PChar;
-  e: PChar;
 begin
-  if FSrc='' then exit;
-  UniqueString(FSrc);
-  p:=PChar(FSrc);
-  e:=p+length(FSrc);
-  while p<e do begin
-    UTF8FixBroken(p);
-    inc(p,UTF8CharacterLength(p));
-  end;
+  UTF8FixBroken(FSrc);
 end;
 
 procedure Init;
diff --git a/docs/xml/lazutils/lazutf8.xml b/docs/xml/lazutils/lazutf8.xml
index b6112a647a..e2df4f4d28 100644
--- a/docs/xml/lazutils/lazutf8.xml
+++ b/docs/xml/lazutils/lazutf8.xml
@@ -278,7 +278,7 @@ It returns 0 if the codepoint can not be represented as a 1 to 4 byte UTF-8 sequ
       </element>
       <!-- procedure Visibility: default -->
       <element name="UTF8FixBroken">
-        <short/>
+        <short>Replaces all invalid UTF8 characters with spaces. Stops at #0.</short>
         <descr/>
         <errors/>
         <seealso/>
diff --git a/ide/ideprocs.pp b/ide/ideprocs.pp
index 5bd7e69909..99118046d9 100644
--- a/ide/ideprocs.pp
+++ b/ide/ideprocs.pp
@@ -1706,10 +1706,8 @@ begin
   for i:=1 to length(Result) do
     if Result[i] in [#0..#31,#127] then Result[i]:=' ';
   if Result='' then exit;
-  if FixUTF8 then begin
-    UniqueString(Result);
-    UTF8FixBroken(PChar(Result));
-  end;
+  if FixUTF8 then
+    UTF8FixBroken(Result);
   Result:=UTF8Trim(Result);
 end;