diff --git a/Projects/AthGeneration/externals/Herwig3.cmake b/Projects/AthGeneration/externals/Herwig3.cmake
index 38f86b97b05ebd697e46462c8db09079e169f3ed..5f56250d942ca80913a8a930fe8558b2f9c7215a 100644
--- a/Projects/AthGeneration/externals/Herwig3.cmake
+++ b/Projects/AthGeneration/externals/Herwig3.cmake
@@ -2,6 +2,6 @@
 # File specifying the location of Herwig3 to use.
 #
 
-set( HERWIG3_LCGVERSION 7.2.1p3 )
+set( HERWIG3_LCGVERSION 7.1.6p3 )
 set( HERWIG3_LCGROOT
    ${LCG_RELEASE_DIR}/MCGenerators/herwig++/${HERWIG3_LCGVERSION}/${LCG_PLATFORM} )
diff --git a/Projects/AthGeneration/externals/Pythia8.cmake b/Projects/AthGeneration/externals/Pythia8.cmake
index 3cc1759c0c8a728821f2f4643985307e0f05b6c0..43df41a55f1915744646fcbfb4745ed0099eb219 100644
--- a/Projects/AthGeneration/externals/Pythia8.cmake
+++ b/Projects/AthGeneration/externals/Pythia8.cmake
@@ -1,7 +1,7 @@
 #
-# File specifying the location of Pythia 8 to use.
+#  File specifying the location of Pythia 8 to use.
 #
 
-set( PYTHIA8_LCGVERSION 240p4 )
+set( PYTHIA8_LCGVERSION 302p3 )
 set( PYTHIA8_LCGROOT
    ${LCG_RELEASE_DIR}/MCGenerators/pythia8/${PYTHIA8_LCGVERSION}/${LCG_PLATFORM} )
diff --git a/Projects/AthGeneration/externals/ThePEG.cmake b/Projects/AthGeneration/externals/ThePEG.cmake
index ec6cc12cadba852c4e7c14922d9043f0e77e77ea..0272efb7441e27950dc2618cedaffbd438670961 100644
--- a/Projects/AthGeneration/externals/ThePEG.cmake
+++ b/Projects/AthGeneration/externals/ThePEG.cmake
@@ -2,6 +2,6 @@
 # File specifying the location of ThePEG to use.
 #
 
-set( THEPEG_LCGVERSION 2.2.1p3 )
+set( THEPEG_LCGVERSION 2.1.6p3 )
 set( THEPEG_LCGROOT
    ${LCG_RELEASE_DIR}/MCGenerators/thepeg/${THEPEG_LCGVERSION}/${LCG_PLATFORM} )