diff --git a/testsuite/isc2023/input/pot3d.dat b/testsuite/isc2023/input/pot3d.dat
index fc52405..55b9c9d 100644
--- a/testsuite/isc2023/input/pot3d.dat
+++ b/testsuite/isc2023/input/pot3d.dat
@@ -24,7 +24,7 @@
   bpfile='bp.h5'
   br_photo_file=''
   ncghist=100
-  ncgmax=10000000
+  ncgmax=40000
   epscg=1.e-12
   idebug=0
  /