diff --git a/include/bitcoin/database/impl/query/merkle.ipp b/include/bitcoin/database/impl/query/merkle.ipp
index da8adb424..1cd5f7448 100644
--- a/include/bitcoin/database/impl/query/merkle.ipp
+++ b/include/bitcoin/database/impl/query/merkle.ipp
@@ -67,7 +67,7 @@ hash_digest CLASS::get_merkle_root(size_t height) const NOEXCEPT
 
 // static/protected
 TEMPLATE
-CLASS::positions CLASS::merkle_branch(size_t leaf, size_t leaves,
+positions CLASS::merkle_branch(size_t leaf, size_t leaves,
     bool compress) NOEXCEPT
 {
     using namespace system;
diff --git a/include/bitcoin/database/query.hpp b/include/bitcoin/database/query.hpp
index e22917ffa..1688fa4a0 100644
--- a/include/bitcoin/database/query.hpp
+++ b/include/bitcoin/database/query.hpp
@@ -787,8 +787,6 @@ class query
 
     /// merkle
     /// -----------------------------------------------------------------------
-    struct position { size_t sibling; size_t width; };
-    using positions = std::vector<position>;
 
     // merkle related utilities
     static hash_digest partial_subroot(hashes&& tree, size_t span) NOEXCEPT;
diff --git a/include/bitcoin/database/types.hpp b/include/bitcoin/database/types.hpp
index 8dcf4540e..84b843bac 100644
--- a/include/bitcoin/database/types.hpp
+++ b/include/bitcoin/database/types.hpp
@@ -81,6 +81,9 @@ using counts = std::pair<size_t, size_t>;
 using sizes = std::pair<size_t, size_t>;
 using heights = std_vector<size_t>;
 
+struct position { size_t sibling; size_t width; };
+using positions = std::vector<position>;
+
 struct header_state { header_link link; code ec; };
 using header_states = std::vector<header_state>;
 
diff --git a/test/query/merkle.cpp b/test/query/merkle.cpp
index 204c9f14a..0c01a2bae 100644
--- a/test/query/merkle.cpp
+++ b/test/query/merkle.cpp
@@ -40,7 +40,6 @@ class merkle_accessor
 {
 public:
     using base = test::query_accessor;
-    using positions = base::positions;
     using base::base;
     using base::merkle_branch;
     using base::interval_span;
@@ -113,7 +112,7 @@ BOOST_AUTO_TEST_CASE(query_merkle___merkle_branch__seven__six_four_and_zero)
 
 BOOST_AUTO_TEST_CASE(block__merkle_branch__medium_power_of_two__expected)
 {
-    const merkle_accessor::positions expected{ { 14, 1 }, { 6, 2 }, { 2, 4 }, { 0, 8 } };
+    const positions expected{ { 14, 1 }, { 6, 2 }, { 2, 4 }, { 0, 8 } };
 
     auto branch = merkle_accessor::merkle_branch(15, 16, true);
     BOOST_REQUIRE_EQUAL(branch.size(), 4u);