diff --git a/sphinx/ext/pngmath.py b/sphinx/ext/pngmath.py
index 745bdba41..1c17ecfeb 100644
--- a/sphinx/ext/pngmath.py
+++ b/sphinx/ext/pngmath.py
@@ -234,10 +234,10 @@ def html_visit_displaymath(self, node):
 
 def setup(app):
     mathbase_setup(app, (html_visit_math, None), (html_visit_displaymath, None))
-    app.add_config_value('pngmath_dvipng', 'dvipng', False)
-    app.add_config_value('pngmath_latex', 'latex', False)
-    app.add_config_value('pngmath_use_preview', False, False)
-    app.add_config_value('pngmath_dvipng_args', ['-gamma 1.5', '-D 110'], False)
-    app.add_config_value('pngmath_latex_args', [], False)
-    app.add_config_value('pngmath_latex_preamble', '', False)
+    app.add_config_value('pngmath_dvipng', 'dvipng', False, 'html')
+    app.add_config_value('pngmath_latex', 'latex', False, 'html')
+    app.add_config_value('pngmath_use_preview', False, 'html')
+    app.add_config_value('pngmath_dvipng_args', ['-gamma 1.5', '-D 110'], 'html')
+    app.add_config_value('pngmath_latex_args', [], 'html')
+    app.add_config_value('pngmath_latex_preamble', '', 'html')
     app.connect('build-finished', cleanup_tempdir)