diff --git a/pkg/shaman/cleanup_test.go b/pkg/shaman/cleanup_test.go
index a9fd3692..ce74fed1 100644
--- a/pkg/shaman/cleanup_test.go
+++ b/pkg/shaman/cleanup_test.go
@@ -23,7 +23,6 @@
 package shaman
 
 import (
-	"errors"
 	"fmt"
 	"io/fs"
 	"os"
@@ -199,7 +198,7 @@ func TestGCComponents(t *testing.T) {
 	assert.FileExists(t, absPaths["6001.blob"], "file should exist after GC")
 	assert.FileExists(t, absPaths["781.blob"], "file should exist after GC")
 	_, err = os.Stat(absPaths["7488.blob"])
-	assert.True(t, errors.Is(err, fs.ErrNotExist), "file %s should NOT exist after GC", absPaths["7488.blob"])
+	assert.ErrorIs(t, err, fs.ErrNotExist, "file %s should NOT exist after GC", absPaths["7488.blob"])
 }
 
 // Test of the high-level GCStorage() function.
@@ -245,9 +244,9 @@ func TestGarbageCollect(t *testing.T) {
 	assert.FileExists(t, absPaths["7488.blob"], "file should exist after dry-run GC")
 	server.GCStorage(false)
 	_, err = os.Stat(absPaths["6001.blob"])
-	assert.True(t, errors.Is(err, fs.ErrNotExist), "file %s should NOT exist after GC", absPaths["6001.blob"])
+	assert.ErrorIs(t, err, fs.ErrNotExist, "file %s should NOT exist after GC", absPaths["6001.blob"])
 	_, err = os.Stat(absPaths["7488.blob"])
-	assert.True(t, errors.Is(err, fs.ErrNotExist), "file %s should NOT exist after GC", absPaths["7488.blob"])
+	assert.ErrorIs(t, err, fs.ErrNotExist, "file %s should NOT exist after GC", absPaths["7488.blob"])
 
 	// Used files should still exist.
 	assert.FileExists(t, absPaths["781.blob"])