diff --git a/CMakeLists.txt b/CMakeLists.txt
index b18530b..471a120 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,7 +10,29 @@ project(
 find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
 find_package(pybind11 2.4.3 REQUIRED)
 
-set(matplotlibcpp17_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include")
+
+# check matplotlib minor version
+execute_process(
+  COMMAND
+  "python3" "-c"
+  "import matplotlib;
+print(str(matplotlib.__version__))"
+  RESULT_VARIABLE MATPLOTLIB_VERSION_CHECKING
+  OUTPUT_VARIABLE MATPLOTLIB_VERSION
+  )
+
+if(NOT MATPLOTLIB_VERSION_CHECKING MATCHES 0)
+  message(FATAL_ERROR
+    "Could not check matplotlib.__version__")
+endif()
+message("Detected matplotlib version is ${MATPLOTLIB_VERSION}")
+if(${MATPLOTLIB_VERSION} VERSION_LESS 3.4)
+  message(WARNING "Detected matplotlib version is < 3.4.0")
+  set(MATPLOTLIB_MINOR_VER_GTE_4 0)
+else()
+  set(MATPLOTLIB_MINOR_VER_GTE_4 1)
+endif()
+
 
 # gallery
 if(NOT DEFINED USE_GUI)
@@ -20,6 +42,8 @@ if(NOT DEFINED ADD_DEMO)
   set(ADD_DEMO 1)
 endif()
 
+set(matplotlibcpp17_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include")
+
 function(add_demo name path)
   add_executable(${name} ${path})
   target_include_directories(${name} PUBLIC
@@ -33,7 +57,7 @@ if(${ADD_DEMO})
   find_package(Python3 COMPONENTS NumPy REQUIRED)
   find_package(xtensor 0.24.0 REQUIRED)
   set(CMAKE_CXX_STANDARD 17)
-  set(CMAKE_CXX_FLAGS "-Wall -g -DUSE_GUI=${USE_GUI}")
+  set(CMAKE_CXX_FLAGS "-Wall -g -DUSE_GUI=${USE_GUI} -DMATPLOTLIB_MINOR_VER_GTE_4=${MATPLOTLIB_MINOR_VER_GTE_4}")
   add_subdirectory(gallery/lines_bars_and_markers)
   add_subdirectory(gallery/subplots_axes_and_figures)
   add_subdirectory(gallery/statistics)
diff --git a/gallery/shapes_and_collections/patch_collection.cpp b/gallery/shapes_and_collections/patch_collection.cpp
index 41e4554..3450c9e 100644
--- a/gallery/shapes_and_collections/patch_collection.cpp
+++ b/gallery/shapes_and_collections/patch_collection.cpp
@@ -60,6 +60,7 @@ int main() {
   py::list colors = py::cast(colors_);
   auto p = collections::PatchCollection(Args(patches), Kwargs("alpha"_a = 0.4));
   p.set_array(Args(colors));
+  // NOTE: error in python3.6.9 ?
   ax.add_collection(Args(p.unwrap()));
   fig.colorbar(Args(p.unwrap()), Kwargs("ax"_a = ax.unwrap()));
 #if USE_GUI
diff --git a/include/matplotlibcpp17/axes.h b/include/matplotlibcpp17/axes.h
index 5ea63cb..41ff7e8 100644
--- a/include/matplotlibcpp17/axes.h
+++ b/include/matplotlibcpp17/axes.h
@@ -206,7 +206,11 @@ struct DECL_STRUCT_ATTR Axes : public BaseWrapper {
     LOAD_FUNC_ATTR(add_patch, self);
     LOAD_FUNC_ATTR(axhline, self);
     LOAD_FUNC_ATTR(bar, self);
+#if MATPLOTLIB_MINOR_VER_GTE_4
     LOAD_FUNC_ATTR(bar_label, self);
+#else
+    WARN_MSG("Not loading bar_label because matplotlib version is < 3.4.0");
+#endif
     LOAD_FUNC_ATTR(barh, self);
     LOAD_FUNC_ATTR(contour, self);
     LOAD_FUNC_ATTR(fill, self);
@@ -227,7 +231,7 @@ struct DECL_STRUCT_ATTR Axes : public BaseWrapper {
       plot_surface_attr = self.attr("plot_surface");
       plot_wireframe_attr = self.attr("plot_wireframe");
       set_zlabel_attr = self.attr("set_zlabel");
-      std::cout << "Loaded Axes3D." << std::endl;
+      INFO_MSG("Loaded Axes3D");
     }
     catch(...) {}
     LOAD_FUNC_ATTR(quiver, self);
@@ -325,8 +329,14 @@ container::BarContainer Axes::bar(const pybind11::tuple &args,
 // bar_label
 pybind11::object Axes::bar_label(const pybind11::tuple &args,
                                  const pybind11::dict &kwargs) {
+#if MATPLOTLIB_MINOR_VER_GTE_4
   pybind11::object ret = bar_label_attr(*args, **kwargs);
   return ret;
+#else
+  ERROR_MSG(
+      "Call to bar_label is invalid because matplotlib version is < 3.4.0");
+  std::exit(0);
+#endif
 }
 
 // barh
diff --git a/include/matplotlibcpp17/common.h b/include/matplotlibcpp17/common.h
index 639030a..a1029f7 100644
--- a/include/matplotlibcpp17/common.h
+++ b/include/matplotlibcpp17/common.h
@@ -8,6 +8,26 @@
 
 #define DECL_STRUCT_ATTR __attribute__((visibility("hidden")))
 
+#include <iostream>
+
+#define INFO_MSG(msg)                                                          \
+  do {                                                                         \
+    std::cout << "Info [" __FILE__ << "@" << __LINE__ << "]: ";                \
+    std::cout << #msg << std::endl;                                            \
+  } while (0)
+
+#define WARN_MSG(msg)                                                          \
+  do {                                                                         \
+    std::cout << "Warn [" __FILE__ << "@" << __LINE__ << "]: ";                \
+    std::cout << #msg << std::endl;                                            \
+  } while (0)
+
+#define ERROR_MSG(msg)                                                         \
+  do {                                                                         \
+    std::cerr << "Error [" __FILE__ << "@" << __LINE__ << "]: ";               \
+    std::cerr << #msg << std::endl;                                            \
+  } while (0)
+
 #include <pybind11/pybind11.h>
 
 namespace matplotlibcpp17 {