--- a/RegressionTests__CompressionStreamTest.st	Wed Nov 22 11:10:37 2017 +0100
+++ b/RegressionTests__CompressionStreamTest.st	Thu Jan 18 09:53:53 2018 +0100
@@ -266,7 +266,7 @@
     "
    |original compressed contents in out zip|
 
-   original := 'smalltalk.rc' asFilename contentsOfEntireFile.
+   original := self originalTestFileContent.
 
    in := original readStream.
 
@@ -299,6 +299,10 @@
         ^ self
    ].
    Transcript showCR:'OK'.
+!
+
+originalTestFileContent
+    ^ OperatingSystem pathOfSTXExecutable asFilename directory / 'smalltalk.rc' asFilename contentsOfEntireFile
 ! !
 
 !CompressionStreamTest methodsFor:'tests'!
@@ -317,7 +321,7 @@
     "
    |fileContents in zip out gzipCmd|
 
-   fileContents := 'smalltalk.rc' asFilename contentsOfEntireFile.
+   fileContents := self originalTestFileContent.
 
    in  := fileContents readStream.
    out := FileStream newFileNamed:'YYY.gz'.