diff --git a/test/unit/geometry/geometry_equal.hpp b/test/unit/geometry/geometry_equal.hpp
index c0819aed1..e7e7b13e5 100644
--- a/test/unit/geometry/geometry_equal.hpp
+++ b/test/unit/geometry/geometry_equal.hpp
@@ -128,7 +128,7 @@ struct geometry_equal_visitor
             REQUIRE(false);
         }
 
-        for(auto const& p : zip_crange(ls1, ls2))
+        for (auto const p : zip_crange(ls1, ls2))
         {
             REQUIRE(p.template get<0>().x == Approx(p.template get<1>().x));
             REQUIRE(p.template get<0>().y == Approx(p.template get<1>().y));
@@ -143,7 +143,7 @@ struct geometry_equal_visitor
             REQUIRE(false);
         }
 
-        for (auto const& p : zip_crange(p1, p2))
+        for (auto const p : zip_crange(p1, p2))
         {
             (*this)(static_cast<std::vector<point<T>> const&>(p.template get<0>()),
                     static_cast<std::vector<point<T>> const&>(p.template get<1>()));
@@ -173,7 +173,7 @@ struct geometry_equal_visitor
             REQUIRE(false);
         }
 
-        for (auto const& ls : zip_crange(mls1, mls2))
+        for (auto const ls : zip_crange(mls1, mls2))
         {
             (*this)(ls.template get<0>(),ls.template get<1>());
         }
@@ -187,7 +187,7 @@ struct geometry_equal_visitor
             REQUIRE(false);
         }
 
-        for (auto const& poly : zip_crange(mpoly1, mpoly2))
+        for (auto const poly : zip_crange(mpoly1, mpoly2))
         {
             (*this)(poly.template get<0>(),poly.template get<1>());
         }
@@ -203,7 +203,7 @@ struct geometry_equal_visitor
             REQUIRE(false);
         }
 
-        for (auto const& g : zip_crange(c1, c2))
+        for (auto const g : zip_crange(c1, c2))
         {
             assert_g_equal(g.template get<0>(),g.template get<1>());
         }
@@ -217,7 +217,7 @@ struct geometry_equal_visitor
             REQUIRE(false);
         }
 
-        for (auto const& g : zip_crange(c1, c2))
+        for (auto const g : zip_crange(c1, c2))
         {
             assert_g_equal(g.template get<0>(),g.template get<1>());
         }