diff --git a/mysql-test/r/gis-rtree.result b/mysql-test/r/gis-rtree.result
index c394aec8851..22c30479125 100644
--- a/mysql-test/r/gis-rtree.result
+++ b/mysql-test/r/gis-rtree.result
@@ -1576,3 +1576,23 @@ a	ASTEXT(b)
 0	POINT(1 1)
 DROP TABLE t1;
 End of 5.1 tests
+CREATE TABLE t1 (
+l LINESTRING NOT NULL,
+SPATIAL KEY(l)
+) ENGINE = myisam;
+INSERT INTO t1 VALUES(GeomFromText('LINESTRING(0 0, 1 1)'));
+INSERT INTO t1 VALUES(GeomFromText('LINESTRING(1 1, 2 2)'));
+INSERT INTO t1 VALUES(GeomFromText('LINESTRING(2 2, 3 3)'));
+SELECT COUNT(*) FROM t1 IGNORE INDEX(l) WHERE MBRContains(l, GEOMFROMTEXT('POINT(0 0)'));
+COUNT(*)
+1
+SELECT COUNT(*) FROM t1 IGNORE INDEX(l) WHERE MBRWithin(GEOMFROMTEXT('POINT(0 0)'), l);
+COUNT(*)
+1
+SELECT COUNT(*) FROM t1 FORCE INDEX(l) WHERE MBRContains(l, GEOMFROMTEXT('POINT(0 0)'));
+COUNT(*)
+1
+SELECT COUNT(*) FROM t1 FORCE INDEX(l) WHERE MBRWithin(GEOMFROMTEXT('POINT(0 0)'), l);
+COUNT(*)
+1
+DROP TABLE t1;
diff --git a/mysql-test/t/gis-rtree.test b/mysql-test/t/gis-rtree.test
index 731efe5648e..404f0447f56 100644
--- a/mysql-test/t/gis-rtree.test
+++ b/mysql-test/t/gis-rtree.test
@@ -956,3 +956,23 @@ SELECT a, ASTEXT(b) FROM t1;
 DROP TABLE t1;
 
 --echo End of 5.1 tests
+
+#
+# MDEV-4521 MBRContains, MBRWithin no longer work with geometries of different type.
+# 
+CREATE TABLE t1 (
+  l LINESTRING NOT NULL,
+  SPATIAL KEY(l)
+) ENGINE = myisam;
+
+INSERT INTO t1 VALUES(GeomFromText('LINESTRING(0 0, 1 1)'));
+INSERT INTO t1 VALUES(GeomFromText('LINESTRING(1 1, 2 2)'));
+INSERT INTO t1 VALUES(GeomFromText('LINESTRING(2 2, 3 3)'));
+
+SELECT COUNT(*) FROM t1 IGNORE INDEX(l) WHERE MBRContains(l, GEOMFROMTEXT('POINT(0 0)'));
+SELECT COUNT(*) FROM t1 IGNORE INDEX(l) WHERE MBRWithin(GEOMFROMTEXT('POINT(0 0)'), l);
+
+SELECT COUNT(*) FROM t1 FORCE INDEX(l) WHERE MBRContains(l, GEOMFROMTEXT('POINT(0 0)'));
+SELECT COUNT(*) FROM t1 FORCE INDEX(l) WHERE MBRWithin(GEOMFROMTEXT('POINT(0 0)'), l);
+
+DROP TABLE t1;
diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 1209e7c9223..5d71ec71903 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -7294,6 +7294,14 @@ static SEL_TREE *get_full_func_mm_tree(RANGE_OPT_PARAM *param,
 		          param->current_table);
   DBUG_ENTER("get_full_func_mm_tree");
 
+#ifdef HAVE_SPATIAL
+  if (field_item->field->type() == MYSQL_TYPE_GEOMETRY)
+  {
+    /* We have to be able to store all sorts of spatial features here */
+    ((Field_geom*) field_item->field)->geom_type= Field::GEOM_GEOMETRY;
+  }
+#endif /*HAVE_SPATIAL*/
+
   for (uint i= 0; i < cond_func->arg_count; i++)
   {
     Item *arg= cond_func->arguments()[i]->real_item();