diff --git a/exercises/practice/circular-buffer/source/circular_buffer.d b/exercises/practice/circular-buffer/source/circular_buffer.d
index 01aea16d..93cb26de 100644
--- a/exercises/practice/circular-buffer/source/circular_buffer.d
+++ b/exercises/practice/circular-buffer/source/circular_buffer.d
@@ -1,5 +1,34 @@
 module circular;
 
+class Buffer(ElementType)
+{
+public:
+    this(size_t capacity)
+    {
+        // implement this function
+    }
+
+    ElementType pop()
+    {
+        // implement this function
+    }
+
+    void push(ElementType element)
+    {
+        // implement this function
+    }
+
+    void clear()
+    {
+        // implement this function
+    }
+
+    void forcePush(ElementType element)
+    {
+        // implement this function
+    }
+}
+
 unittest
 {
     import std.exception : assertThrown;
diff --git a/exercises/practice/run-length-encoding/source/run_length_encoding.d b/exercises/practice/run-length-encoding/source/run_length_encoding.d
index 63c4a0a2..5322bedc 100644
--- a/exercises/practice/run-length-encoding/source/run_length_encoding.d
+++ b/exercises/practice/run-length-encoding/source/run_length_encoding.d
@@ -1,5 +1,15 @@
 module run_length_encoding;
 
+pure string encode(immutable string input)
+{
+    // implement this function
+}
+
+pure string decode(immutable string input)
+{
+    // implement this function
+}
+
 unittest
 {
     immutable int allTestsEnabled = 0;
diff --git a/exercises/practice/sum-of-multiples/source/sum_of_multiples.d b/exercises/practice/sum-of-multiples/source/sum_of_multiples.d
index 7b221496..0641ab82 100644
--- a/exercises/practice/sum-of-multiples/source/sum_of_multiples.d
+++ b/exercises/practice/sum-of-multiples/source/sum_of_multiples.d
@@ -1,5 +1,10 @@
 module sum_of_multiples;
 
+pure int calculateSum(immutable int[] factors, immutable int limit)
+{
+    // implement this function
+}
+
 unittest
 {
     immutable int allTestsEnabled = 0;