diff --git a/python-calmjs.parse.changes b/python-calmjs.parse.changes
index e1b64c5..3b64636 100644
--- a/python-calmjs.parse.changes
+++ b/python-calmjs.parse.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Tue Jan 14 14:37:01 UTC 2020 - pgajdos@suse.com
+
+- fix build in SLE-15: set en_US.UTF-8 encoding
+
 -------------------------------------------------------------------
 Mon Jan  6 15:13:55 UTC 2020 - Tomáš Chvátal <tchvatal@suse.com>
 
diff --git a/python-calmjs.parse.spec b/python-calmjs.parse.spec
index 0eb65c1..49d26da 100644
--- a/python-calmjs.parse.spec
+++ b/python-calmjs.parse.spec
@@ -42,6 +42,7 @@ ECMAScript; a near feature complete fork of slimit.
 %setup -q -n calmjs.parse-%{version}
 
 %build
+LANG=en_US.UTF-8
 %python_build
 
 %install
@@ -51,6 +52,7 @@ ECMAScript; a near feature complete fork of slimit.
 %python_expand %fdupes %{buildroot}%{$python_sitelib}
 
 %check
+LANG=en_US.UTF-8
 %pytest
 
 %files %{python_files}