diff --git a/exercises/practice/resistor-color-duo/.meta/tests.toml b/exercises/practice/resistor-color-duo/.meta/tests.toml
index 5b5e59a3..9036fc78 100644
--- a/exercises/practice/resistor-color-duo/.meta/tests.toml
+++ b/exercises/practice/resistor-color-duo/.meta/tests.toml
@@ -18,8 +18,14 @@ description = "Blue and grey"
 [f1886361-fdfd-4693-acf8-46726fe24e0c]
 description = "Yellow and violet"
 
+[b7a6cbd2-ae3c-470a-93eb-56670b305640]
+description = "White and red"
+
 [77a8293d-2a83-4016-b1af-991acc12b9fe]
 description = "Orange and orange"
 
 [0c4fb44f-db7c-4d03-afa8-054350f156a8]
 description = "Ignore additional colors"
+
+[4a8ceec5-0ab4-4904-88a4-daf953a5e818]
+description = "Black and brown, one-digit"
diff --git a/exercises/practice/resistor-color-duo/source/resistor_color_duo.d b/exercises/practice/resistor-color-duo/source/resistor_color_duo.d
index e592decf..3ec7338d 100644
--- a/exercises/practice/resistor-color-duo/source/resistor_color_duo.d
+++ b/exercises/practice/resistor-color-duo/source/resistor_color_duo.d
@@ -1,5 +1,13 @@
 module resistor_color_duo;
 
+class ResistorColorDuo
+{
+    static pure long value(immutable string[] colorsInput)
+    {
+        // implement this function
+    }
+}
+
 unittest
 {
     immutable int allTestsEnabled = 0;
@@ -15,11 +23,17 @@ unittest
         // Yellow and violet
         assert(ResistorColorDuo.value(["yellow", "violet"]) == 47);
 
+        // White and red
+        assert(ResistorColorDuo.value(["white", "red"]) == 92);
+
         // Orange and orange
         assert(ResistorColorDuo.value(["orange", "orange"]) == 33);
 
         // Ignore additional colors
         assert(ResistorColorDuo.value(["green", "brown", "orange"]) == 51);
+
+        // Black and brown, one-digit
+        assert(ResistorColorDuo.value(["black", "brown"]) == 1);
     }
 
 }