diff --git a/src/librt/primitives/datum/datum.c b/src/librt/primitives/datum/datum.c
index 2edf9d5588..2f836ee197 100644
--- a/src/librt/primitives/datum/datum.c
+++ b/src/librt/primitives/datum/datum.c
@@ -368,6 +368,36 @@ rt_datum_export5(struct bu_external *ep, const struct rt_db_internal *ip, double
     return 0;
 }
 
+int
+rt_datum_mat(struct rt_db_internal *rop, const mat_t mat, const struct rt_db_internal *ip)
+{
+    if (!rop || !mat)
+	return BRLCAD_OK;
+
+    // For the moment, we only support applying a mat to a datum in place - the
+    // input and output must be the same.
+    if (ip && rop != ip) {
+	bu_log("rt_datum_mat:  alignment of data between multiple datums is unsupported - input datum must be the same as the output datum.\n");
+	return BRLCAD_ERROR;
+    }
+
+    struct rt_datum_internal *datum_ip = (struct rt_datum_internal *)rop->idb_ptr;
+    RT_DATUM_CK_MAGIC(datum_ip);
+
+    vect_t v;
+    while (datum_ip) {
+	VMOVE(v, datum_ip->pnt);
+	MAT4X3PNT(datum_ip->pnt, mat, v);
+	if (MAGNITUDE(datum_ip->dir) > 0.0) {
+	    VMOVE(v, datum_ip->dir);
+	    MAT4X3PNT(datum_ip->dir , mat, v);
+	}
+	datum_ip = datum_ip->next;
+    }
+
+    return BRLCAD_OK;
+}
+
 
 /**
  * Import datums from the database format to the internal format.
@@ -412,9 +442,9 @@ rt_datum_import5(struct rt_db_internal *ip, const struct bu_external *ep, const
 	    first = datum_ip;
 
 	if (vals >= ELEMENTS_PER_POINT)
-	    MAT4X3PNT(datum_ip->pnt, mat, vec);
+	    VMOVE(datum_ip->pnt, vec);
 	if (vals >= ELEMENTS_PER_POINT + ELEMENTS_PER_VECT)
-	    MAT4X3VEC(datum_ip->dir, mat, vec+3);
+	    VMOVE(datum_ip->dir, vec+3);
 	if (vals == MAX_VALS)
 	    datum_ip->w = vec[6];
 
@@ -430,7 +460,8 @@ rt_datum_import5(struct rt_db_internal *ip, const struct bu_external *ep, const
     ip->idb_type = ID_DATUM;
     ip->idb_major_type = DB5_MAJORTYPE_BRLCAD;
 
-    return 0;			/* OK */
+    /* Apply transform */
+    return rt_datum_mat(ip, mat, ip);
 }
 
 
diff --git a/src/librt/primitives/table.cpp b/src/librt/primitives/table.cpp
index 8002662eb9..fba1a1b16e 100644
--- a/src/librt/primitives/table.cpp
+++ b/src/librt/primitives/table.cpp
@@ -2418,7 +2418,7 @@ const struct rt_functab OBJ[] = {
 	NULL, /* serialize */
 	NULL, /* label */
 	RTFUNCTAB_FUNC_KEYPOINT_CAST(rt_datum_keypoint), /* keypoint */
-	NULL, /* mat */
+	RTFUNCTAB_FUNC_MAT_CAST(rt_datum_mat),
 	NULL  /* perturb */
     },