diff --git a/test/unit/core/expressions_test.cpp b/test/unit/core/expressions_test.cpp
index 6c2d1580a..24ad86a33 100644
--- a/test/unit/core/expressions_test.cpp
+++ b/test/unit/core/expressions_test.cpp
@@ -65,6 +65,7 @@ TEST_CASE("expressions")
                             { "grass" , tr.transcode("grow")},
                             { "wind"  , tr.transcode("blow")},
                             { "sky"   , tr.transcode("is blue")},
+                            { "τ"     , mapnik::value_double(6.2831853)},
                             { "double", mapnik::value_double(1.23456)},
                             { "int"   , mapnik::value_integer(123)},
                             { "bool"  , mapnik::value_bool(true)},
@@ -74,8 +75,6 @@ TEST_CASE("expressions")
     auto eval = std::bind(evaluate_string, feature, _1);
     auto approx = Approx::custom().epsilon(1e-6);
 
-    TRY_CHECK(eval(" [foo]='bar' ") == true);
-
     // primary expressions
     // null
     TRY_CHECK(parse_and_dump("null") == "null");
@@ -98,6 +97,17 @@ TEST_CASE("expressions")
     TRY_CHECK(parse_and_dump("deg_to_rad") == "0.0174533");
     TRY_CHECK(parse_and_dump("rad_to_deg") == "57.2958");
 
+    // ascii attribute name
+    TRY_CHECK(eval(" [foo]='bar' ") == true);
+
+    // unicode attribute name
+    TRY_CHECK(eval("[τ]") == prop.at("τ"));
+    TRY_CHECK(eval("[τ]") == eval(u8"[\u03C4]"));
+
+    // change to TRY_CHECK once \u1234 escape sequence in attribute name
+    // is implemented in expression grammar
+    CHECK_NOFAIL(eval("[τ]") == eval("[\\u03C3]"));
+
     // unary functions
     // sin / cos
     TRY_CHECK(eval(" sin(0.25 * pi) / cos(0.25 * pi) ").to_double() == approx(1.0));