diff --git a/modules/core/include/opencv2/core/cvdef.h b/modules/core/include/opencv2/core/cvdef.h
index 0b3d5328f1..86e4a30ef1 100644
--- a/modules/core/include/opencv2/core/cvdef.h
+++ b/modules/core/include/opencv2/core/cvdef.h
@@ -395,11 +395,12 @@ typedef union Cv64suf
 Cv64suf;
 
 #ifndef OPENCV_ABI_COMPATIBILITY
-#define OPENCV_ABI_COMPATIBILITY 400
+#define OPENCV_ABI_COMPATIBILITY 500
 #endif
 
 #ifdef __OPENCV_BUILD
-#  define DISABLE_OPENCV_3_COMPATIBILITY
+#  define DISABLE_OPENCV_3_COMPATIBILITY  // OpenCV 5.0: remove that
+#  define DISABLE_OPENCV_4_COMPATIBILITY
 #  define OPENCV_DISABLE_DEPRECATED_COMPATIBILITY
 #endif
 
diff --git a/modules/core/include/opencv2/core/mat.hpp b/modules/core/include/opencv2/core/mat.hpp
index de2370f46b..68744f970b 100644
--- a/modules/core/include/opencv2/core/mat.hpp
+++ b/modules/core/include/opencv2/core/mat.hpp
@@ -170,9 +170,6 @@ public:
         STD_VECTOR        = 3 << KIND_SHIFT,
         STD_VECTOR_VECTOR = 4 << KIND_SHIFT,
         STD_VECTOR_MAT    = 5 << KIND_SHIFT,
-#if OPENCV_ABI_COMPATIBILITY < 500
-        EXPR              = 6 << KIND_SHIFT,  //!< removed: https://github.com/opencv/opencv/pull/17046
-#endif
         OPENGL_BUFFER     = 7 << KIND_SHIFT,
         CUDA_HOST_MEM     = 8 << KIND_SHIFT,
         CUDA_GPU_MAT      = 9 << KIND_SHIFT,
@@ -180,9 +177,6 @@ public:
         STD_VECTOR_UMAT   =11 << KIND_SHIFT,
         STD_BOOL_VECTOR   =12 << KIND_SHIFT,
         STD_VECTOR_CUDA_GPU_MAT = 13 << KIND_SHIFT,
-#if OPENCV_ABI_COMPATIBILITY < 500
-        STD_ARRAY         =14 << KIND_SHIFT,  //!< removed: https://github.com/opencv/opencv/issues/18897
-#endif
         STD_ARRAY_MAT     =15 << KIND_SHIFT
     };
 
diff --git a/modules/core/test/test_mat.cpp b/modules/core/test/test_mat.cpp
index a5d844e7ad..9366db6a2f 100644
--- a/modules/core/test/test_mat.cpp
+++ b/modules/core/test/test_mat.cpp
@@ -1985,7 +1985,6 @@ class TestInputArrayRangeChecking {
         #define C(x) case cv::_InputArray::x: return #x
         C(MAT);
         C(UMAT);
-        C(EXPR);
         C(MATX);
         C(STD_VECTOR);
         C(NONE);