diff --git a/src/auto_map.c b/src/auto_map.c
index 039251e3..64b65fb5 100644
--- a/src/auto_map.c
+++ b/src/auto_map.c
@@ -74,20 +74,6 @@ typedef enum KeysArrayType{
     KAT_DTas,
 } KeysArrayType;
 
-NPY_DATETIMEUNIT
-dt_unit_from_array(PyArrayObject* a) {
-    // This is based on get_datetime_metadata_from_dtype in the NumPy source, but that function is private. This does not check that the dytpe is of the appropriate type.
-    PyArray_Descr* dt = PyArray_DESCR(a); // borrowed ref
-    PyArray_DatetimeMetaData* dma = &(((PyArray_DatetimeDTypeMetaData *)PyDataType_C_METADATA(dt))->meta);
-    return dma->base;
-}
-
-NPY_DATETIMEUNIT
-dt_unit_from_scalar(PyDatetimeScalarObject* dts) {
-    // Based on convert_pyobject_to_datetime and related usage in datetime.c
-    PyArray_DatetimeMetaData* dma = &(dts->obmeta);
-    return dma->base;
-}
 
 KeysArrayType
 at_to_kat(int array_t, PyArrayObject* a) {
@@ -123,7 +109,7 @@ at_to_kat(int array_t, PyArrayObject* a) {
             return KAT_STRING;
 
         case NPY_DATETIME: {
-            NPY_DATETIMEUNIT dtu = dt_unit_from_array(a);
+            NPY_DATETIMEUNIT dtu = AK_dt_unit_from_array(a);
             switch (dtu) {
                 case NPY_FR_Y:
                     return KAT_DTY;
@@ -685,9 +671,6 @@ lookup_hash_obj(FAMObject *self, PyObject *key, Py_hash_t hash)
     int result = -1;
     Py_hash_t h = 0;
 
-    // AK_DEBUG_MSG_OBJ("lookup_hash_obj", key);
-    // TODO: if key is a dt64, we need to get the units and compare to units before doing PyObject_RichCompareBool
-
     while (1) {
         for (Py_ssize_t i = 0; i < SCAN; i++) {
             h = table[table_pos].hash;
@@ -702,6 +685,16 @@ lookup_hash_obj(FAMObject *self, PyObject *key, Py_hash_t hash)
             if (guess == key) { // Hit. Object ID comparison
                 return table_pos;
             }
+
+            // if key is a dt64, only do PyObject_RichCompareBool if units match
+            if (PyArray_IsScalar(key, Datetime) && PyArray_IsScalar(guess, Datetime)) {
+                if (AK_dt_unit_from_scalar((PyDatetimeScalarObject *)key)
+                    != AK_dt_unit_from_scalar((PyDatetimeScalarObject *)guess)) {
+                    table_pos++;
+                    continue;
+                }
+            }
+
             result = PyObject_RichCompareBool(guess, key, Py_EQ);
             if (result < 0) { // Error.
                 return -1;
@@ -1030,10 +1023,9 @@ lookup_datetime(FAMObject *self, PyObject* key) {
     if (PyArray_IsScalar(key, Datetime)) {
         v = (npy_int64)PyArrayScalar_VAL(key, Datetime);
         // if we observe a NAT, we skip unit checks
-        // AK_DEBUG_MSG_OBJ("dt64 value", PyLong_FromLongLong(v));
 
         if (v != NPY_DATETIME_NAT) {
-            NPY_DATETIMEUNIT key_unit = dt_unit_from_scalar(
+            NPY_DATETIMEUNIT key_unit = AK_dt_unit_from_scalar(
                     (PyDatetimeScalarObject *)key);
             if (!kat_is_datetime_unit(self->keys_array_type, key_unit)) {
                 return -1;
@@ -1872,7 +1864,7 @@ fam_get_all(FAMObject *self, PyObject *key) {
                     GET_ALL_FLEXIBLE(char, char_get_end_p, lookup_hash_string, string_to_hash, PyBytes_FromStringAndSize);
                     break;
                 case NPY_DATETIME: {
-                    NPY_DATETIMEUNIT key_unit = dt_unit_from_array(key_array);
+                    NPY_DATETIMEUNIT key_unit = AK_dt_unit_from_array(key_array);
                     if (!kat_is_datetime_unit(self->keys_array_type, key_unit)) {
                         PyErr_SetString(PyExc_KeyError, "datetime64 units do not match");
                         Py_DECREF(array);
@@ -2070,7 +2062,7 @@ fam_get_any(FAMObject *self, PyObject *key) {
                     GET_ANY_FLEXIBLE(char, char_get_end_p, lookup_hash_string, string_to_hash);
                     break;
                 case NPY_DATETIME: {
-                    NPY_DATETIMEUNIT key_unit = dt_unit_from_array(key_array);
+                    NPY_DATETIMEUNIT key_unit = AK_dt_unit_from_array(key_array);
                     if (!kat_is_datetime_unit(self->keys_array_type, key_unit)) {
                         return values;
                     }
diff --git a/src/tri_map.c b/src/tri_map.c
index 48c41c47..6eb0c7d1 100644
--- a/src/tri_map.c
+++ b/src/tri_map.c
@@ -11,15 +11,6 @@
 # include "tri_map.h"
 # include "utilities.h"
 
-static inline NPY_DATETIMEUNIT
-AK_dt_unit_from_array(PyArrayObject* a) {
-    // This is based on get_datetime_metadata_from_dtype in the NumPy source, but that function is private. This does not check that the dtype is of the appropriate type.
-    PyArray_Descr* dt = PyArray_DESCR(a); // borrowed ref
-    PyArray_DatetimeMetaData* dma = &(((PyArray_DatetimeDTypeMetaData *)PyDataType_C_METADATA(dt))->meta);
-    // PyArray_DatetimeMetaData* dma = &(((PyArray_DatetimeDTypeMetaData *)PyArray_DESCR(a)->c_metadata)->meta);
-    return dma->base;
-}
-
 typedef struct TriMapOne {
     Py_ssize_t from; // signed
     Py_ssize_t to;
diff --git a/src/utilities.h b/src/utilities.h
index 9b85a198..660681c0 100644
--- a/src/utilities.h
+++ b/src/utilities.h
@@ -9,6 +9,7 @@
 # define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
 
 # include "numpy/arrayobject.h"
+# include "numpy/arrayscalars.h"
 
 static const size_t UCS4_SIZE = sizeof(Py_UCS4);
 
@@ -318,4 +319,20 @@ AK_nonzero_1d(PyArrayObject* array) {
     return final;
 }
 
+static inline NPY_DATETIMEUNIT
+AK_dt_unit_from_array(PyArrayObject* a) {
+    // This is based on get_datetime_metadata_from_dtype in the NumPy source, but that function is private. This does not check that the dtype is of the appropriate type.
+    PyArray_Descr* dt = PyArray_DESCR(a); // borrowed ref
+    PyArray_DatetimeMetaData* dma = &(((PyArray_DatetimeDTypeMetaData *)PyDataType_C_METADATA(dt))->meta);
+    // PyArray_DatetimeMetaData* dma = &(((PyArray_DatetimeDTypeMetaData *)PyArray_DESCR(a)->c_metadata)->meta);
+    return dma->base;
+}
+
+static inline NPY_DATETIMEUNIT
+AK_dt_unit_from_scalar(PyDatetimeScalarObject* dts) {
+    // Based on convert_pyobject_to_datetime and related usage in datetime.c
+    PyArray_DatetimeMetaData* dma = &(dts->obmeta);
+    return dma->base;
+}
+
 #endif  /* ARRAYKIT_SRC_UTILITIES_H_ */