diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
index 164fe80..1ba4037 100644
--- a/app/CMakeLists.txt
+++ b/app/CMakeLists.txt
@@ -23,13 +23,16 @@ set(
         ${CMAKE_SOURCE_DIR}/../opencv-3-4-15
 )
 
-# register a library to import...
+# register the opencv header files...
+include_directories(${lib_src_dir}/native/jni/include)
+
+# register a new library to import...
 add_library(
         lib_opencv
         SHARED
         IMPORTED
 )
-# ...and assign the corresponding location of the precompiled library
+# ...and assign the corresponding location of the precompiled opencv library
 set_target_properties(
         lib_opencv
         PROPERTIES
@@ -37,22 +40,16 @@ set_target_properties(
         ${lib_src_dir}/native/libs/${ANDROID_ABI}/libopencv_java3.so
 )
 
-# register another library to import...
+# register the custom c++ code of the app as library
 add_library(
         native_opencv
         SHARED
-        src/main/cpp/native_opencv.cpp # register the source code of the custom c++ code
-)
-# ...and assign the location of the c++ text files of the opencv lib
-target_include_directories(
-        native_opencv
-        PRIVATE
-        ${lib_src_dir}/native/jni/include
+        src/main/cpp/native_opencv.cpp
 )
 
 # link the required libs together
 target_link_libraries(
-        native_opencv # includes source code and opencv source file
+        native_opencv # includes the custom c++ code of the app
         lib_opencv # includes the precompiled opencv lib
         android # include android sdk
         log # include android logging sdk
diff --git a/app/build.gradle b/app/build.gradle
index 0ff6082..8135da9 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -10,17 +10,31 @@ android {
         applicationId = 'com.michaeltroger.featureMatchingNative'
         minSdkVersion 14
         targetSdkVersion 30
-        versionCode = 2
-        versionName = '1.1'
-        ndk {
-            abiFilters 'armeabi-v7a', 'x86'
-        }
+        versionCode = 3
+        versionName = '1.2'
+        ndk.abiFilters 'x86', 'armeabi-v7a'
+        //only x86 abis specified here
+        //a workaround with build variants was required to allow x64 support too
+        //the issue was that the custom c++ code was not compiled and copied into the
+        //x64 apks when minsdk set to 14. x64 is supported since minsdk 21 only
         externalNativeBuild {
             cmake {
                 cppFlags "-fexceptions", "-frtti"
             }
         }
     }
+    flavorDimensions "api"
+    productFlavors {
+        minApi14 {  // default variant with only x86 support but works with all devices
+            dimension "api"
+        }
+        minApi21 { //choose this build variant to get x64 support (recommended on modern devices)
+            dimension "api"
+            minSdkVersion 21
+            ndk.abiFilters += 'x86_64'
+            ndk.abiFilters += 'arm64-v8a'
+        }
+    }
     buildTypes {
         release {
             minifyEnabled false