diff --git a/cmake/toolchain/heptools-dev-base.cmake b/cmake/toolchain/heptools-dev-base.cmake
index 72c88751d3acab1b97ef603cc086df6feaaf710a..b002fa874013ab0ee4bff0fc460c7290dcefd62c 100644
--- a/cmake/toolchain/heptools-dev-base.cmake
+++ b/cmake/toolchain/heptools-dev-base.cmake
@@ -163,7 +163,7 @@ LCG_external_package(debugpy           1.3.0
 LCG_external_package(DecayLanguage     0.18.5                                   )
 LCG_external_package(decorator         5.0.9                                    )
 LCG_external_package(defusedxml        0.7.1                                    )
-LCG_external_package(delphes           3.5.1pre09                               )
+LCG_external_package(delphes           3.5.1pre12                               )
 LCG_external_package(deprecated        1.2.13                                   )
 LCG_external_package(deprecation       2.1.0                                    )
 LCG_external_package(dill              0.3.8                                    )