diff --git a/ndn-cpp/c/util/DynamicUCharArray.c b/ndn-cpp/c/util/DynamicUCharArray.c
index ac1e451..83016ce 100644
--- a/ndn-cpp/c/util/DynamicUCharArray.c
+++ b/ndn-cpp/c/util/DynamicUCharArray.c
@@ -8,6 +8,21 @@
 
 char *ndn_DynamicUCharArray_reallocArray(struct ndn_DynamicUCharArray *self, unsigned int length)
 {
-  // TODO: implement.
-  return "ndn_DynamicUCharArray_reallocArray: realloc function pointer not supplied";
+  if (!self->realloc)
+    return "ndn_DynamicUCharArray_reallocArray: realloc function pointer not supplied";
+  
+  // See if double is enough.
+  unsigned int newLength = self->length * 2;
+  if (length > newLength)
+    // The needed length is much greater, so use it.
+    newLength = length;
+    
+  unsigned char *newArray = (*self->realloc)(self->array, newLength);
+  if (!newArray)
+    return "ndn_DynamicUCharArray_reallocArray: realloc failed";
+  
+  self->array = newArray;
+  self->length = newLength;
+  
+  return 0;
 }
\ No newline at end of file