diff --git a/cmake/templates/NSIS.template.in b/cmake/templates/NSIS.template.in
index e73fcc0eff..16151fd34b 100644
--- a/cmake/templates/NSIS.template.in
+++ b/cmake/templates/NSIS.template.in
@@ -928,54 +928,6 @@ Function HandlePostInstallOptions
 
 FunctionEnd
 
-; StrContains
-; This function does a case sensitive searches for an occurrence of a substring in a string.
-; It returns the substring if it is found.
-; Otherwise it returns null("").
-; Written by kenglish_hi
-; Adapted from StrReplace written by dandaman32
-
-Var STR_HAYSTACK
-Var STR_NEEDLE
-Var STR_CONTAINS_VAR_1
-Var STR_CONTAINS_VAR_2
-Var STR_CONTAINS_VAR_3
-Var STR_CONTAINS_VAR_4
-Var STR_RETURN_VAR
-
-Function StrContains
-  Exch $STR_NEEDLE
-  Exch 1
-  Exch $STR_HAYSTACK
-  ; Uncomment to debug
-  ;MessageBox MB_OK 'STR_NEEDLE = $STR_NEEDLE STR_HAYSTACK = $STR_HAYSTACK '
-    StrCpy $STR_RETURN_VAR ""
-    StrCpy $STR_CONTAINS_VAR_1 -1
-    StrLen $STR_CONTAINS_VAR_2 $STR_NEEDLE
-    StrLen $STR_CONTAINS_VAR_4 $STR_HAYSTACK
-    loop:
-      IntOp $STR_CONTAINS_VAR_1 $STR_CONTAINS_VAR_1 + 1
-      StrCpy $STR_CONTAINS_VAR_3 $STR_HAYSTACK $STR_CONTAINS_VAR_2 $STR_CONTAINS_VAR_1
-      StrCmp $STR_CONTAINS_VAR_3 $STR_NEEDLE found
-      StrCmp $STR_CONTAINS_VAR_1 $STR_CONTAINS_VAR_4 done
-      Goto loop
-    found:
-      StrCpy $STR_RETURN_VAR $STR_NEEDLE
-      Goto done
-    done:
-   Pop $STR_NEEDLE ;Prevent "invalid opcode" errors and keep the
-   Exch $STR_RETURN_VAR
-FunctionEnd
-
-!macro _StrContainsConstructor OUT NEEDLE HAYSTACK
-  Push `${HAYSTACK}`
-  Push `${NEEDLE}`
-  Call StrContains
-  Pop `${OUT}`
-!macroend
-
-!define StrContains '!insertmacro "_StrContainsConstructor"'
-
 ;--------------------------------
 ; determine admin versus local install
 Function un.onInit
@@ -984,9 +936,7 @@ Function un.onInit
   ; If the $EXEPATH does not contain the $TEMP dir, this instance is not the copied one
   ; so we move it to the $TEMP dir and then execute the copied uninstaller.
 
-  ${StrContains} $0 $TEMP $EXEPATH
-
-  ${If} $0 == "notfound"
+  ${If} $EXEDIR != $TEMP
     CopyFiles /SILENT $EXEPATH $TEMP\Uninstall.exe
     ExecWait '"$Temp\Uninstall.exe" _?=$INSTDIR' $0
     SetErrorLevel $0