diff --git a/workspace-server/internal/provisioner/cp_provisioner_test.go b/workspace-server/internal/provisioner/cp_provisioner_test.go
index 75b366b22..99f266f43 100644
--- a/workspace-server/internal/provisioner/cp_provisioner_test.go
+++ b/workspace-server/internal/provisioner/cp_provisioner_test.go
@@ -236,7 +236,7 @@ func TestStart_SendsTemplateAndGeneratedConfigFiles(t *testing.T) {
 	if err := os.WriteFile(filepath.Join(tmpl, "config.yaml"), []byte("name: template\n"), 0o600); err != nil {
 		t.Fatal(err)
 	}
-	if err := os.WriteFile(filepath.Join(tmpl, "adapter.py"), bytes.Repeat([]byte("x"), cpConfigFilesMaxBytes), 0o600); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpl, "adapter.py"), bytes.Repeat([]byte("x"), cpConfigFilesMaxBytes-100), 0o600); err != nil {
 		t.Fatal(err)
 	}
 	if err := os.Mkdir(filepath.Join(tmpl, "prompts"), 0o700); err != nil {