Index: build/ac-macros/java.m4
===================================================================
--- build/ac-macros/java.m4	(revision 21764)
+++ build/ac-macros/java.m4	(working copy)
@@ -4,6 +4,7 @@
 
 AC_DEFUN(SVN_CHECK_JDK,
 [
+  JAVA_OLDEST_WORKING_VER="$1"
   AC_ARG_WITH(jdk,
               AC_HELP_STRING([--with-jdk=PATH],
                              [Try to use 'PATH/include' to find the JNI
@@ -15,10 +16,10 @@
         JDK_SUITABLE=no
       ;;
       "yes")
-        SVN_FIND_JDK(check)
+        SVN_FIND_JDK(check, $JAVA_OLDEST_WORKING_VER)
       ;;
       *)
-        SVN_FIND_JDK($withval)
+        SVN_FIND_JDK($withval, $JAVA_OLDEST_WORKING_VER)
       ;;
     esac
   ],
@@ -30,6 +31,7 @@
 AC_DEFUN(SVN_FIND_JDK,
 [
   where=$1
+  JAVA_OLDEST_WORKING_VER="$2"
 
   JDK=none
   JAVA_BIN=none
@@ -131,8 +133,11 @@
     fi
 
     dnl Add javac flags.
+    # The release for "-source" could actually be greater than that
+    # of "-target", if we want to cross-compile for lesser JVMs.
+    JAVAC_FLAGS="-target $JAVA_OLDEST_WORKING_VER -source 1.2"
     if test "$enable_debugging" = "yes"; then
-      JAVAC_FLAGS="-g"
+      JAVAC_FLAGS="-g $JAVAC_FLAGS"
     fi
 
     JNI_INCLUDES="-I$JNI_INCLUDEDIR"
Index: build/generator/gen_win.py
===================================================================
--- build/generator/gen_win.py	(revision 21764)
+++ build/generator/gen_win.py	(working copy)
@@ -318,7 +318,8 @@
 
           sourcepath = self.path(source.sourcepath)
 
-          cbuild = "javac -g -classpath %s -d %s -sourcepath %s $(InputPath)" \
+          cbuild = "javac -g -target 1.2 -source 1.2 -classpath %s -d %s " \
+                   "-sourcepath %s $(InputPath)" \
                    % tuple(map(self.quote, (classes, targetdir, sourcepath)))
 
           ctarget = self.path(object.filename)
Index: configure.in
===================================================================
--- configure.in	(revision 21764)
+++ configure.in	(working copy)
@@ -553,8 +553,10 @@
 fi
 AC_PATH_PROGS(PYTHON, "$PYTHON", none)
 
+# The minimum version for the JVM runtime for our Java bytecode.
+JAVA_OLDEST_WORKING_VER='1.2'
 # SVN_CHECK_JDK sets $JAVA_CLASSPATH
-SVN_CHECK_JDK
+SVN_CHECK_JDK($JAVA_OLDEST_WORKING_VER)
 
 AC_PATH_PROG(PERL, perl, none)