diff --git a/numpy/core/include/numpy/experimental_dtype_api.h b/numpy/core/include/numpy/experimental_dtype_api.h
index 23e9a8d2160c..1fbd41981029 100644
--- a/numpy/core/include/numpy/experimental_dtype_api.h
+++ b/numpy/core/include/numpy/experimental_dtype_api.h
@@ -336,8 +336,9 @@ typedef int (PyArrayMethod_StridedLoop)(PyArrayMethod_Context *context,
 #define NPY_DT_default_descr 3
 #define NPY_DT_common_dtype 4
 #define NPY_DT_common_instance 5
-#define NPY_DT_setitem 6
-#define NPY_DT_getitem 7
+#define NPY_DT_ensure_canonical 6
+#define NPY_DT_setitem 7
+#define NPY_DT_getitem 8
 
 
 // TODO: These slots probably still need some thought, and/or a way to "grow"?
@@ -457,7 +458,7 @@ PyArray_GetDefaultDescr(PyArray_DTypeMeta *DType)
  */
 #if !defined(NO_IMPORT) && !defined(NO_IMPORT_ARRAY)
 
-#define __EXPERIMENTAL_DTYPE_VERSION 4
+#define __EXPERIMENTAL_DTYPE_VERSION 5
 
 static int
 import_experimental_dtype_api(int version)
diff --git a/numpy/core/src/multiarray/experimental_public_dtype_api.c b/numpy/core/src/multiarray/experimental_public_dtype_api.c
index 441dbdc1ff64..36350c83209f 100644
--- a/numpy/core/src/multiarray/experimental_public_dtype_api.c
+++ b/numpy/core/src/multiarray/experimental_public_dtype_api.c
@@ -16,7 +16,7 @@
 #include "common_dtype.h"
 
 
-#define EXPERIMENTAL_DTYPE_API_VERSION 4
+#define EXPERIMENTAL_DTYPE_API_VERSION 5
 
 
 typedef struct{
@@ -117,7 +117,7 @@ PyArray_ArrFuncs default_funcs = {
 
 
 /* other slots are in order, so keep only last around: */
-#define NUM_DTYPE_SLOTS 7
+#define NUM_DTYPE_SLOTS 8
 
 
 int