diff --git a/CMakeLists.txt b/CMakeLists.txt
index 31935e0e..e2f3d716 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,28 +1,27 @@
 cmake_minimum_required (VERSION 2.6)
-project (hnsw_lib)
+project(hnsw_lib
+    LANGUAGES CXX)
 
-include_directories("${PROJECT_BINARY_DIR}")
+add_library(hnswlib INTERFACE)
+target_include_directories(hnswlib INTERFACE .) 
 
+if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
+    set(CMAKE_CXX_STANDARD 11)
 
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+      SET( CMAKE_CXX_FLAGS  "-Ofast -DNDEBUG -std=c++11 -DHAVE_CXX0X -openmp -march=native -fpic -ftree-vectorize")
+    elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+      SET( CMAKE_CXX_FLAGS  "-Ofast -lrt -DNDEBUG -std=c++11 -DHAVE_CXX0X -march=native -fpic -w -fopenmp -ftree-vectorize -ftree-vectorizer-verbose=0" )
+    elseif (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      SET( CMAKE_CXX_FLAGS  "-Ofast -lrt -DNDEBUG -std=c++11 -DHAVE_CXX0X -openmp -march=native -fpic -w -fopenmp -ftree-vectorize" )
+    endif()
 
-set(SOURCE_EXE main.cpp)           
+    add_executable(test_updates examples/updates_test.cpp)
+    target_link_libraries(test_updates hnswlib)
 
-set(SOURCE_LIB sift_1b.cpp)
+    add_executable(searchKnnCloserFirst_test examples/searchKnnCloserFirst_test.cpp)
+    target_link_libraries(searchKnnCloserFirst_test hnswlib)
 
-add_library(sift_test STATIC ${SOURCE_LIB})
-
-
-add_executable(main ${SOURCE_EXE})
-if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-  SET( CMAKE_CXX_FLAGS  "-Ofast -DNDEBUG -std=c++11 -DHAVE_CXX0X -openmp -march=native -fpic -ftree-vectorize")
-elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-SET( CMAKE_CXX_FLAGS  "-Ofast -lrt -DNDEBUG -std=c++11 -DHAVE_CXX0X -openmp -march=native -fpic -w -fopenmp -ftree-vectorize -ftree-vectorizer-verbose=0" )
-elseif (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
-  SET( CMAKE_CXX_FLAGS  "-Ofast -lrt -DNDEBUG -std=c++11 -DHAVE_CXX0X -openmp -march=native -fpic -w -fopenmp -ftree-vectorize" )
+    add_executable(main main.cpp sift_1b.cpp)
+    target_link_libraries(main hnswlib)
 endif()
-
-add_executable(test_updates examples/updates_test.cpp)
-
-add_executable(searchKnnCloserFirst_test examples/searchKnnCloserFirst_test.cpp)
-
-target_link_libraries(main sift_test) 
diff --git a/hnswlib/hnswalg.h b/hnswlib/hnswalg.h
index f23c17d9..2bd2eb5e 100644
--- a/hnswlib/hnswalg.h
+++ b/hnswlib/hnswalg.h
@@ -744,7 +744,7 @@ namespace hnswlib {
         }
 
         template<typename data_t>
-        std::vector<data_t> getDataByLabel(labeltype label)
+        std::vector<data_t> getDataByLabel(labeltype label) const
         {
             tableint label_c;
             auto search = label_lookup_.find(label);
diff --git a/hnswlib/visited_list_pool.h b/hnswlib/visited_list_pool.h
index 6b0f4458..5e1a4a58 100644
--- a/hnswlib/visited_list_pool.h
+++ b/hnswlib/visited_list_pool.h
@@ -2,6 +2,7 @@
 
 #include <mutex>
 #include <string.h>
+#include <deque>
 
 namespace hnswlib {
     typedef unsigned short int vl_type;