diff --git a/src/Makefile.am b/src/Makefile.am
index d99478802..a81f11253 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -243,7 +243,7 @@ DISTCLEANFILES += \
 	$(HB_GOBJECT_ENUM_headers) \
 	$(NULL)
 hb-gobject-enums.%: hb-gobject-enums.%.tmpl $(HBHEADERS)
-	$(AM_V_GEN) $(GLIB_MKENUMS) \
+	$(AM_V_GEN) PYTHONIOENCODING=UTF-8 $(GLIB_MKENUMS) \
 		--identifier-prefix hb_ --symbol-prefix hb_gobject \
 		--template $^ | \
 	sed 's/_t_get_type/_get_type/g; s/_T (/ (/g' > "$@" \
diff --git a/src/gen-def.py b/src/gen-def.py
index 74507e46d..de35eb7d0 100755
--- a/src/gen-def.py
+++ b/src/gen-def.py
@@ -7,7 +7,7 @@ import io, os, re, sys
 headers_content = []
 for h in os.environ["headers"].split (' '):
 	if h.endswith (".h"):
-		with io.open (h, encoding='ISO-8859-1') as f: headers_content.append (f.read ())
+		with io.open (h, encoding='utf-8') as f: headers_content.append (f.read ())
 
 result = """EXPORTS
 %s