2 files changed, 6 insertions, 2 deletions
diff --git a/tests/roots/test-ext-doctest-skipif/conf.py b/tests/roots/test-ext-doctest-skipif/conf.py
index cd8f3eb..ae00e35 100644
--- a/tests/roots/test-ext-doctest-skipif/conf.py
+++ b/tests/roots/test-ext-doctest-skipif/conf.py
@@ -2,7 +2,9 @@ extensions = ['sphinx.ext.doctest']
 
 project = 'test project for the doctest :skipif: directive'
 root_doc = 'skipif'
-source_suffix = '.txt'
+source_suffix = {
+    '.txt': 'restructuredtext'
+}
 exclude_patterns = ['_build']
 
 doctest_global_setup = '''
diff --git a/tests/roots/test-ext-doctest/conf.py b/tests/roots/test-ext-doctest/conf.py
index d0e8b10..57fc406 100644
--- a/tests/roots/test-ext-doctest/conf.py
+++ b/tests/roots/test-ext-doctest/conf.py
@@ -2,5 +2,7 @@ extensions = ['sphinx.ext.doctest']
 
 project = 'test project for doctest'
 root_doc = 'doctest'
-source_suffix = '.txt'
+source_suffix = {
+    '.txt': 'restructuredtext'
+}
 exclude_patterns = ['_build']