diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index aa048ca175b8aa84ac186c02b0d87ba2c0baf9ab..19ef0f76b2a11214d628ee3e4031b7b260bb1133 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -19,7 +19,7 @@ format:
     - cargo +nightly fmt --all -- --check
 
 linux:
-  image: 'rust:1.43.0'
+  image: 'rust:1.53.0'
   cache:
     key: linux
     paths:
diff --git a/tests/string_vars.ion b/tests/string_vars.ion
index d5d86a30875193da2ffb411a3e410f5320c7b205..e2cb353c9e181db5a750319c7630d01e8ae40b1f 100644
--- a/tests/string_vars.ion
+++ b/tests/string_vars.ion
@@ -1,10 +1,10 @@
 echo '# ANCHOR: string_variables'
+# The CI can not handle deletions properly.
 mkdir -p _tmp _tmp/t1 _tmp/t2
 cd _tmp
-let filelist = $(ls ^> /dev/null)
+let filelist = *
 echo $filelist
 cd ..
-rm -fr _tmp
 echo '# ANCHOR_END: string_variables'
 echo '# ANCHOR: string_slicing'
 let foo = "Hello, World"
diff --git a/tests/string_vars.out b/tests/string_vars.out
index de408ddf05295523a510b2d02b524d2d044b206d..99002380b81355dac7f0f6827556bd345224d3b9 100644
--- a/tests/string_vars.out
+++ b/tests/string_vars.out
@@ -1,6 +1,5 @@
 # ANCHOR: string_variables
-t1
-t2
+t1 t2
 # ANCHOR_END: string_variables
 # ANCHOR: string_slicing
 Hello