diff --git a/Configuration/Generator/python/CE_E_Front_120um_cfi.py b/Configuration/Generator/python/CE_E_Front_120um_cfi.py
index 0eaaa43d0be1c..3cd138be329de 100644
--- a/Configuration/Generator/python/CE_E_Front_120um_cfi.py
+++ b/Configuration/Generator/python/CE_E_Front_120um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_E_Front_200um_cfi.py b/Configuration/Generator/python/CE_E_Front_200um_cfi.py
index 9db5c437fe9a6..eeda146bec36e 100644
--- a/Configuration/Generator/python/CE_E_Front_200um_cfi.py
+++ b/Configuration/Generator/python/CE_E_Front_200um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_E_Front_300um_cfi.py b/Configuration/Generator/python/CE_E_Front_300um_cfi.py
index a0083ac2026df..670cea1f7be95 100644
--- a/Configuration/Generator/python/CE_E_Front_300um_cfi.py
+++ b/Configuration/Generator/python/CE_E_Front_300um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_H_Coarse_300um_cfi.py b/Configuration/Generator/python/CE_H_Coarse_300um_cfi.py
index f95859ca97acc..89f31fdbc3e0e 100644
--- a/Configuration/Generator/python/CE_H_Coarse_300um_cfi.py
+++ b/Configuration/Generator/python/CE_H_Coarse_300um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_H_Coarse_Scint_cfi.py b/Configuration/Generator/python/CE_H_Coarse_Scint_cfi.py
index f20bbe6ab2bfd..22ed548dcd941 100644
--- a/Configuration/Generator/python/CE_H_Coarse_Scint_cfi.py
+++ b/Configuration/Generator/python/CE_H_Coarse_Scint_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_H_Fine_120um_cfi.py b/Configuration/Generator/python/CE_H_Fine_120um_cfi.py
index 044e7d0a426f3..b1ecacc0eab68 100644
--- a/Configuration/Generator/python/CE_H_Fine_120um_cfi.py
+++ b/Configuration/Generator/python/CE_H_Fine_120um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_H_Fine_200um_cfi.py b/Configuration/Generator/python/CE_H_Fine_200um_cfi.py
index 0e641843ad6c8..309114bb7ec78 100644
--- a/Configuration/Generator/python/CE_H_Fine_200um_cfi.py
+++ b/Configuration/Generator/python/CE_H_Fine_200um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),
diff --git a/Configuration/Generator/python/CE_H_Fine_300um_cfi.py b/Configuration/Generator/python/CE_H_Fine_300um_cfi.py
index 37a867efa10e0..0466c694460dc 100644
--- a/Configuration/Generator/python/CE_H_Fine_300um_cfi.py
+++ b/Configuration/Generator/python/CE_H_Fine_300um_cfi.py
@@ -12,7 +12,7 @@
         Pointing = cms.bool(True),
         Overlapping = cms.bool(False),
         RandomShoot = cms.bool(False),
-        NParticles = cms.int32(2),
+        NParticles = cms.int32(1),
         MaxEta = cms.double(2.7),
         MinEta = cms.double(1.7),
         MaxPhi = cms.double(3.14159265359),