diff --git a/tools/modelsim/set_modelsim b/tools/modelsim/set_modelsim
index 1af0d22e272f31e755e14e04f2d29853c899922d..ab8da5327d58d4eb1ae32494af6c9d73fd733229 100755
--- a/tools/modelsim/set_modelsim
+++ b/tools/modelsim/set_modelsim
@@ -42,8 +42,9 @@ elif [ "${TOOLSET}" = "unb2" ]; then
   export LD_PRELOAD=/home/software/freetype2/usr/lib/libfreetype.so
 elif [ "${TOOLSET}" = "unb233" ]; then
   # unb233 = toolset unb2 on dop233
+  # however better use 'unb2' and comment the export LD_PRELOAD line when on dop233, because the generate_ip.sh scripts use fixed 'unb2'.
   . ${RADIOHDL}/tools/quartus/quartus_version.sh 14.1
-  . ${RADIOHDL}/tools/modelsim/modelsim_version.sh 10.2c
+  . ${RADIOHDL}/tools/modelsim/modelsim_version.sh 10.4
 else
   echo "error: unknown tool setting: ${TOOLSET} (choose 'unb1' or 'unb2')"
   exit 1