diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1710249..39bd776 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.4)
+cmake_minimum_required(VERSION 3.0)
 project(paraBEM)
 
 MESSAGE(STATUS "python version set: ${py}")
@@ -7,6 +7,7 @@ set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 # OPTIONS
+set (CMAKE_CXX_STANDARD 11)
 OPTION(BUILD_PYTHON_BINDINGS "create python bindings" ON)
 
 if (BUILD_PYTHON_BINDINGS)
@@ -29,6 +30,11 @@ find_package(OpenMP)
 
 ## OPENMP
 if(OPENMP_FOUND)
+
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+        LINK_LIBRARIES(${OpenMP_libomp_LIBRARY})
+        LINK_LIBRARIES(${OpenMP_libomp_LIBRARY})
+    endif()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
     set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   ${OpenMP_C_FLAGS}")
 endif()
diff --git a/README.md b/README.md
index 010dac5..316ce6c 100755
--- a/README.md
+++ b/README.md
@@ -26,9 +26,11 @@ the c++ code is wrapped with pybind11 to python. This allows fast computation (e
 ```bash
 mkdir build && cd build
 cmake ..
-use cmake-gui to fix not found packages or wrong versions (eg. python, pybind11, ...)
+cmake -DPYTHON_EXECUTABLE=/usr/local/bin/python3 ..
 ```
 
+use cmake-gui to fix not found packages or wrong versions (eg. python, pybind11, ...)
+
 ### build and install
 if cmake doesn't complain, install the package. (the number at the end is the number of compile jobs)
 ```
diff --git a/src/panel2.cpp b/src/panel2.cpp
index 70abeb7..cea31ba 100755
--- a/src/panel2.cpp
+++ b/src/panel2.cpp
@@ -47,7 +47,7 @@ Panel2* Panel2::get_neigbour(int nr, Panel2* pan1)
     pan = pan1->points[nr]->panels[1];
     if (pan == this){
       pan = pan1->points[1 - nr]->panels[0];
-      if (pan = pan1){
+      if (pan == pan1){
 	pan = pan1->points[1 - nr]->panels[1];
       }
     }