diff --git a/src/Bindings.cc b/src/Bindings.cc
index 9eb09be..49f57c8 100644
--- a/src/Bindings.cc
+++ b/src/Bindings.cc
@@ -69,7 +69,7 @@ void Bindings::print(std::ostream& stream, const std::string& indent) const {
         variable_names.emplace_back(pair.first);
     }
 
-    sort(variable_names.begin(), variable_names.end());
+    std::sort(variable_names.begin(), variable_names.end());
 
     for (const auto& variable: variable_names) {
         stream << indent;
diff --git a/tests/sub-output.test b/tests/sub-output.test
index bb2fa35..8ac890d 100644
--- a/tests/sub-output.test
+++ b/tests/sub-output.test
@@ -3,11 +3,13 @@ file src/input <>
 source input
 end-of-inline-data
 file build.fninja <>
+sources := src/sub-output
+
 rule a
     command = a $in $out
     flags = --verbose
 
-build top-output: a src/sub-output
+build top-output: a $sources
 
 subninja src/build.fninja
 end-of-inline-data
@@ -21,6 +23,7 @@ file build/build.ninja {} <>
 
 build_directory = .
 source_directory = ..
+sources = src/sub-output
 top_build_directory = .
 top_source_directory = ..