diff -r 51bf28aa18a5 -r 90017a182892 bin/isabelle_java
--- a/bin/isabelle_java	Tue Oct 04 14:32:44 2016 +0200
+++ b/bin/isabelle_java	Tue Oct 04 14:39:31 2016 +0200
@@ -14,7 +14,16 @@
 (
   source "$ISABELLE_HOME/lib/scripts/getsettings" || exit 2
 
-  declare -a JAVA_ARGS; eval "JAVA_ARGS=($ISABELLE_JAVA_SYSTEM_OPTIONS)"
+  case "$ISABELLE_JAVA_PLATFORM" in
+    x86-*)
+      ISABELLE_TOOL_JAVA_OPTIONS="$ISABELLE_TOOL_JAVA_OPTIONS32"
+      ;;
+    x86_64-*)
+      ISABELLE_TOOL_JAVA_OPTIONS="$ISABELLE_TOOL_JAVA_OPTIONS64"
+      ;;
+  esac
+
+  declare -a JAVA_ARGS; eval "JAVA_ARGS=($ISABELLE_JAVA_SYSTEM_OPTIONS $ISABELLE_TOOL_JAVA_OPTIONS)"
 
   if [ -f "$ISABELLE_HOME/src/Tools/jEdit/dist/jedit.jar" ]; then
     classpath "$ISABELLE_HOME/src/Tools/jEdit/dist/jedit.jar"