diff --git a/Projects/AnalysisBase/externals.txt b/Projects/AnalysisBase/externals.txt
index 59c44b2082c5ac256c6d9045dd973fc78790d8ab..b6eea38576bafd3f6c0b9acba3f5ef0d8737405e 100644
--- a/Projects/AnalysisBase/externals.txt
+++ b/Projects/AnalysisBase/externals.txt
@@ -6,4 +6,5 @@
 # forbidden.
 
 # The version of atlas/atlasexternals to use:
-AnalysisBaseExternalsVersion = aa2d4807
\ No newline at end of file
+AnalysisBaseExternalsVersion = 8643cbb2
+
diff --git a/Projects/AnalysisTop/externals.txt b/Projects/AnalysisTop/externals.txt
index d36758ec65fdbd705f2dbc9303d991a4aa23345b..59f0188418445afd159f1ef525bd38386c52548b 100644
--- a/Projects/AnalysisTop/externals.txt
+++ b/Projects/AnalysisTop/externals.txt
@@ -1,4 +1,4 @@
 # Versions of the various externals to build before starting the build of
 # this project, when doing a full stack nightly build.
 
-AnalysisBaseExternalsVersion = aa2d4807
\ No newline at end of file
+AnalysisBaseExternalsVersion = 8643cbb2
diff --git a/Projects/AthSimulation/externals.txt b/Projects/AthSimulation/externals.txt
index 05967a3418935894b62e234d8f55a73e5e765dee..c0305844cdf746ce2250ef5980b590b465842a01 100644
--- a/Projects/AthSimulation/externals.txt
+++ b/Projects/AthSimulation/externals.txt
@@ -6,7 +6,7 @@
 # forbidden.
 
 # The version of atlas/atlasexternals to use:
-AthSimulationExternalsVersion = aa2d4807
+AthSimulationExternalsVersion = 8643cbb2
 
 # The version of atlas/Gaudi to use:
 GaudiVersion = v28r2.011
diff --git a/Projects/Athena/externals.txt b/Projects/Athena/externals.txt
index ca0e9e2ec52f592b91eac50dad69980c457d93a1..4a6dd79fc727d1c28b4f2e3be566865e779a2a0c 100644
--- a/Projects/Athena/externals.txt
+++ b/Projects/Athena/externals.txt
@@ -6,7 +6,7 @@
 # forbidden.
 
 # The version of atlas/atlasexternals to use:
-AthenaExternalsVersion = aa2d4807
+AthenaExternalsVersion = 8643cbb2
 
 # The version of atlas/Gaudi to use:
 GaudiVersion = v28r2.011