diff --git a/src/swcio.cpp b/src/swcio.cpp
index 63eae66d5dd07ed1ccae74cc686c0d3e07977475..ec4a3e862dc437eb03b9ffa0be65192590ca28f5 100644
--- a/src/swcio.cpp
+++ b/src/swcio.cpp
@@ -1,3 +1,4 @@
+#include <algorithm>
 #include <iomanip>
 #include <map>
 #include <sstream>
diff --git a/tests/test_swcio.cpp b/tests/test_swcio.cpp
index 2ca3563abdf6b412a9a14ac3cdd67802fcfc5f92..efd73909b3e2945f7892a881b7103a15b5bdf6d5 100644
--- a/tests/test_swcio.cpp
+++ b/tests/test_swcio.cpp
@@ -234,7 +234,7 @@ TEST(swc_parser, input_cleaning)
         is << "2 1 14.566132 34.873772 7.857000 0.717830 1\n";
 
         auto cells = swc_read_cells(is);
-        EXPECT_EQ(2, cells.size());
+        EXPECT_EQ(2u, cells.size());
     }
 
     {
@@ -246,7 +246,7 @@ TEST(swc_parser, input_cleaning)
         is << "4 1 14.566132 34.873772 7.857000 0.717830 1\n";
 
         auto cells = swc_read_cells(is);
-        EXPECT_EQ(2, cells.size());
+        EXPECT_EQ(2u, cells.size());
     }
 
     {
@@ -259,7 +259,7 @@ TEST(swc_parser, input_cleaning)
 
         std::array<cell_record::id_type, 4> expected_id_list = {{ 0, 1, 2, 3 }};
         auto cells = swc_read_cells(is);
-        ASSERT_EQ(4, cells.size());
+        ASSERT_EQ(4u, cells.size());
         
         auto expected_id = expected_id_list.cbegin();
         for (const auto &c : cells) {
@@ -283,7 +283,7 @@ TEST(swc_parser, input_cleaning)
             {{ 0, 1, 2, 3, 4, 5 }};
         std::array<cell_record::id_type, 6> expected_parent_list =
             {{ -1, 0, 1, 1, 0, 4 }};
-        ASSERT_EQ(6, cells.size());
+        ASSERT_EQ(6u, cells.size());
 
         auto expected_id = expected_id_list.cbegin();
         auto expected_parent = expected_parent_list.cbegin();
@@ -293,7 +293,6 @@ TEST(swc_parser, input_cleaning)
             ++expected_id;
             ++expected_parent;
         }
-        
     }
 }
 
@@ -311,10 +310,10 @@ TEST(cell_record_ranges, raw)
         is << "4 1 14.566132 34.873772 7.857000 0.717830 1\n";
 
         std::vector<cell_record> cells;
-        for (auto &&c : cell_record_range_raw(is)) {
+        for (auto c : cell_record_range_raw(is)) {
             cells.push_back(c);
         }
 
-        EXPECT_EQ(4, cells.size());
+        EXPECT_EQ(4u, cells.size());
     }
 }