diff --git a/tests/auto/sdktool/sdktool.qbs b/tests/auto/sdktool/sdktool.qbs
index bd8b8d267a3..b7928c74875 100644
--- a/tests/auto/sdktool/sdktool.qbs
+++ b/tests/auto/sdktool/sdktool.qbs
@@ -1,4 +1,4 @@
-import qbs
+import qbs.FileInfo
 
 QtcAutotest {
     name: "sdktool autotest"
@@ -8,5 +8,8 @@ QtcAutotest {
         files: "tst_sdktool.cpp"
     }
 
-    cpp.defines: base.concat(['SDKTOOL_DIR="' + qbs.installRoot + '/' + qtc.ide_libexec_path + '"'])
+    cpp.defines: base.concat([
+        'SDKTOOL_DIR="' + FileInfo.joinPaths(FileInfo.fromNativeSeparators(qbs.installRoot),
+                                             qtc.ide_libexec_path) + '"'
+    ])
 }