diff --git a/common/lib/xmodule/xmodule/library_content_module.py b/common/lib/xmodule/xmodule/library_content_module.py
index 2d78cf1e8a..9f80d22d5e 100644
--- a/common/lib/xmodule/xmodule/library_content_module.py
+++ b/common/lib/xmodule/xmodule/library_content_module.py
@@ -407,8 +407,8 @@ class LibraryContentDescriptor(LibraryContentFields, MakoModuleDescriptor, XmlDe
                     StudioValidationMessage.WARNING,
                     (
                         ngettext(
-                            u'The specified libraries are configured to fetch {count} problem, ',
-                            u'The specified libraries are configured to fetch {count} problems, ',
+                            u'The specified library is configured to fetch {count} problem, ',
+                            u'The specified library is configured to fetch {count} problems, ',
                             self.max_count
                         ) +
                         ngettext(
diff --git a/common/lib/xmodule/xmodule/library_tools.py b/common/lib/xmodule/xmodule/library_tools.py
index d1b2c737f3..40afbbb549 100644
--- a/common/lib/xmodule/xmodule/library_tools.py
+++ b/common/lib/xmodule/xmodule/library_tools.py
@@ -104,15 +104,15 @@ class LibraryToolsService(object):
 
     def update_children(self, dest_block, user_id, user_perms=None):
         """
-        This method is to be used when any of the libraries that a LibraryContentModule
-        references have been updated. It will re-fetch all matching blocks from
+        This method is to be used when the library that a LibraryContentModule
+        references has been updated. It will re-fetch all matching blocks from
         the libraries, and copy them as children of dest_block. The children
         will be given new block_ids, but the definition ID used should be the
         exact same definition ID used in the library.
 
-        This method will update dest_block's 'source_libraries' field to store
-        the version number of the libraries used, so we easily determine if
-        dest_block is up to date or not.
+        This method will update dest_block's 'source_library_version' field to
+        store the version number of the libraries used, so we easily determine
+        if dest_block is up to date or not.
         """
         if user_perms and not user_perms.can_write(dest_block.location.course_key):
             raise PermissionDenied()
@@ -125,7 +125,7 @@ class LibraryToolsService(object):
         library_key = dest_block.source_library_key
         library = self._get_library(library_key)
         if library is None:
-            raise ValueError("Required library not found.")
+            raise ValueError("Requested library not found.")
         if user_perms and not user_perms.can_read(library_key):
             raise PermissionDenied()
         filter_children = (dest_block.capa_type != ANY_CAPA_TYPE_VALUE)
diff --git a/common/lib/xmodule/xmodule/tests/test_library_content.py b/common/lib/xmodule/xmodule/tests/test_library_content.py
index 485bfad0ae..1feeddea29 100644
--- a/common/lib/xmodule/xmodule/tests/test_library_content.py
+++ b/common/lib/xmodule/xmodule/tests/test_library_content.py
@@ -126,14 +126,14 @@ class TestLibraryContentModule(LibraryContentTest):
         Test that the validation method of LibraryContent blocks can validate
         the source_library setting.
         """
-        # When source_libraries is blank, the validation summary should say this block needs to be configured:
+        # When source_library_id is blank, the validation summary should say this block needs to be configured:
         self.lc_block.source_library_id = ""
         result = self.lc_block.validate()
         self.assertFalse(result)  # Validation fails due to at least one warning/message
         self.assertTrue(result.summary)
         self.assertEqual(StudioValidationMessage.NOT_CONFIGURED, result.summary.type)
 
-        # When source_libraries references a non-existent library, we should get an error:
+        # When source_library_id references a non-existent library, we should get an error:
         self.lc_block.source_library_id = "library-v1:BAD+WOLF"
         result = self.lc_block.validate()
         self.assertFalse(result)  # Validation fails due to at least one warning/message
@@ -141,7 +141,7 @@ class TestLibraryContentModule(LibraryContentTest):
         self.assertEqual(StudioValidationMessage.ERROR, result.summary.type)
         self.assertIn("invalid", result.summary.text)
 
-        # When source_libraries is set but the block needs to be updated, the summary should say so:
+        # When source_library_id is set but the block needs to be updated, the summary should say so:
         self.lc_block.source_library_id = unicode(self.library.location.library_key)
         result = self.lc_block.validate()
         self.assertFalse(result)  # Validation fails due to at least one warning/message
diff --git a/common/test/acceptance/tests/studio/test_studio_library_container.py b/common/test/acceptance/tests/studio/test_studio_library_container.py
index fa49f339a5..24ec806fef 100644
--- a/common/test/acceptance/tests/studio/test_studio_library_container.py
+++ b/common/test/acceptance/tests/studio/test_studio_library_container.py
@@ -219,7 +219,7 @@ class StudioLibraryContainerTest(StudioLibraryTest, UniqueCourseTest):
         And I set Problem Type selector so "Any"
         Then I can see that "No matching content" warning is shown
         """
-        expected_tpl = "The specified libraries are configured to fetch {count} problems, " \
+        expected_tpl = "The specified library is configured to fetch {count} problems, " \
                        "but there are only {actual} matching problems."
 
         library_container = self._get_library_xblock_wrapper(self.unit_page.xblocks[1])