diff --git a/src/format.hpp b/src/format.hpp
index 4d3efa68c..64cb82f25 100644
--- a/src/format.hpp
+++ b/src/format.hpp
@@ -13,6 +13,6 @@
 #define FMT_HEADER_ONLY
 #include <fmt/format.h>
 
-using namespace fmt::literals;
+using namespace fmt::literals; // NOLINT(google-global-names-in-headers)
 
 #endif // OSM2PGSQL_FORMAT_HPP
diff --git a/src/middle-ram.cpp b/src/middle-ram.cpp
index d7be6add1..85cfcbe56 100644
--- a/src/middle-ram.cpp
+++ b/src/middle-ram.cpp
@@ -83,6 +83,7 @@ bool middle_ram_t::way_get(osmid_t id, osmium::memory::Buffer *buffer) const
         return false;
     }
 
+    // NOLINTNEXTLINE(google-build-using-namespace)
     using namespace osmium::builder::attr;
     osmium::builder::add_way(*buffer, _id(id), _tags(ele->tags),
                              _nodes(ele->ndids));
@@ -120,6 +121,7 @@ bool middle_ram_t::relation_get(osmid_t id,
         return false;
     }
 
+    // NOLINTNEXTLINE(google-build-using-namespace)
     using namespace osmium::builder::attr;
     osmium::builder::add_relation(*buffer, _id(id),
                                   _members(ele->members.for_builder()),
diff --git a/src/osmtypes.hpp b/src/osmtypes.hpp
index 29d907c55..f77291c16 100644
--- a/src/osmtypes.hpp
+++ b/src/osmtypes.hpp
@@ -38,13 +38,13 @@ struct member
     osmid_t id;
     std::string role;
 
-    explicit operator osmium::builder::attr::member_type const() const
+    explicit operator osmium::builder::attr::member_type() const
     {
         return osmium::builder::attr::member_type(type, id, role.c_str());
     }
 
-    member(osmium::item_type t, osmid_t i, std::string const &r)
-    : type(t), id(i), role(r)
+    member(osmium::item_type t, osmid_t i, std::string r)
+    : type(t), id(i), role(std::move(r))
     {}
 };
 
@@ -73,13 +73,14 @@ struct tag_t
     std::string key;
     std::string value;
 
-    operator std::pair<char const *, char const *> const() const noexcept
+    operator std::pair<char const *, char const *>() const noexcept
     {
         return std::pair<char const *, char const *>(key.c_str(),
                                                      value.c_str());
     }
 
-    tag_t(std::string const &k, std::string const &v) : key(k), value(v) {}
+    tag_t(std::string k, std::string v) : key(std::move(k)), value(std::move(v))
+    {}
 };
 
 /**
diff --git a/src/progress-display.cpp b/src/progress-display.cpp
index 8b31d0053..1456f74b7 100644
--- a/src/progress-display.cpp
+++ b/src/progress-display.cpp
@@ -25,7 +25,7 @@ static double count_per_second(osmid_t count, uint64_t elapsed) noexcept
     return static_cast<double>(count) / elapsed;
 }
 
-static std::string cps_display(osmid_t count, uint64_t elapsed) noexcept
+static std::string cps_display(osmid_t count, uint64_t elapsed)
 {
     double const cps = count_per_second(count, elapsed);
 
diff --git a/src/progress-display.hpp b/src/progress-display.hpp
index d8ce5e398..9ff2d6fcf 100644
--- a/src/progress-display.hpp
+++ b/src/progress-display.hpp
@@ -41,7 +41,8 @@ class progress_display_t : public osmium::handler::Handler
     };
 
 public:
-    progress_display_t(bool enabled = false) noexcept : m_enabled(enabled)
+    explicit progress_display_t(bool enabled = false) noexcept
+    : m_enabled(enabled)
     {
         m_node.start = std::time(nullptr);
     }