diff --git a/Makefile.am b/Makefile.am
index 582b38f7..b05890b3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -651,7 +651,8 @@ $(JCXX): $(srcdir)/$(JSWG) $(JDOC) bindings/swig/classes.i bindings/swig/enums.i
 		$(bindings_cxx_libsigrokcxx_la_include_HEADERS) \
 		$(nodist_bindings_cxx_libsigrokcxx_la_include_HEADERS)
 	-$(AM_V_at)rm -f $(java_cleanfiles)
-	$(AM_V_GEN)$(SWIG) -c++ -Dnoexcept= -java -package org.sigrok.core.classes \
+	$(AM_V_GEN)$(SWIG) -c++ -Dnoexcept= -Dprivate=protected \
+		-java -package org.sigrok.core.classes \
 		-Ibindings -I$(JCLS) $(local_includes) -I$(srcdir) $(JNI_CPPFLAGS) \
 		-outdir $(JCLS) -o $@ $(srcdir)/$(JSWG)
 
diff --git a/bindings/python/setup.py b/bindings/python/setup.py
index c70fffca..e38acc75 100644
--- a/bindings/python/setup.py
+++ b/bindings/python/setup.py
@@ -87,8 +87,9 @@ setup(
     ext_modules = [
         Extension('sigrok.core._classes',
             sources = [vpath('sigrok/core/classes.i')],
-            swig_opts = ['-c++', '-threads', '-Dnoexcept=', '-Isigrok/core',
-                '-I..', '-I' + srcdir_parent] + ['-I%s' % i for i in includes],
+            swig_opts = ['-c++', '-threads', '-Dnoexcept=', '-Dprivate=protected',
+                '-Isigrok/core', '-I..', '-I' + srcdir_parent] +
+                ['-I%s' % i for i in includes],
             extra_compile_args = ['-Wno-uninitialized'],
             include_dirs = includes,
             library_dirs = libdirs,