diff --git a/src/flex-lua-geom.cpp b/src/flex-lua-geom.cpp
index 314c8f001..7fc0f5631 100644
--- a/src/flex-lua-geom.cpp
+++ b/src/flex-lua-geom.cpp
@@ -98,7 +98,7 @@ static int geom_centroid(lua_State *lua_state)
 static int geom_geometry_n(lua_State *lua_state)
 {
     auto const *const input_geometry = unpack_geometry(lua_state);
-    int const index = luaL_checkinteger(lua_state, 2);
+    auto const index = static_cast<int>(luaL_checkinteger(lua_state, 2));
 
     try {
         auto *geom = create_lua_geometry_object(lua_state);
@@ -216,7 +216,7 @@ static int geom_tostring(lua_State *lua_state)
 static int geom_transform(lua_State *lua_state)
 {
     auto const *const input_geometry = unpack_geometry(lua_state);
-    int const srid = luaL_checkinteger(lua_state, 2);
+    auto const srid = static_cast<int>(luaL_checkinteger(lua_state, 2));
 
     try {
         if (input_geometry->srid() != 4326) {
diff --git a/src/geom-functions.cpp b/src/geom-functions.cpp
index 41c278b60..4eff87aaf 100644
--- a/src/geom-functions.cpp
+++ b/src/geom-functions.cpp
@@ -548,7 +548,7 @@ void line_merge(geometry_t *output, geometry_t const &input)
     std::vector<endpoint_t> endpoints;
 
     // ...and a list of connections.
-    constexpr std::size_t const NOCONN = -1UL;
+    constexpr auto const NOCONN = std::numeric_limits<std::size_t>::max();
 
     struct connection_t
     {
diff --git a/src/node-locations.cpp b/src/node-locations.cpp
index 01abbaf5f..4a479c652 100644
--- a/src/node-locations.cpp
+++ b/src/node-locations.cpp
@@ -65,10 +65,10 @@ osmium::Location node_locations_t::get(osmid_t id) const
     for (std::size_t n = 0; n < block_size && begin != end; ++n) {
         auto const bid = did.update(
             static_cast<int64_t>(protozero::decode_varint(&begin, end)));
-        int32_t const x = dx.update(
-            protozero::decode_zigzag64(protozero::decode_varint(&begin, end)));
-        int32_t const y = dy.update(
-            protozero::decode_zigzag64(protozero::decode_varint(&begin, end)));
+        auto const x = static_cast<int32_t>(dx.update(
+            protozero::decode_zigzag64(protozero::decode_varint(&begin, end))));
+        auto const y = static_cast<int32_t>(dy.update(
+            protozero::decode_zigzag64(protozero::decode_varint(&begin, end))));
         if (bid == id) {
             return osmium::Location{x, y};
         }
diff --git a/src/progress-display.cpp b/src/progress-display.cpp
index 94addcc05..78265f864 100644
--- a/src/progress-display.cpp
+++ b/src/progress-display.cpp
@@ -19,7 +19,7 @@ static double count_per_second(std::size_t count, uint64_t elapsed) noexcept
     }
 
     if (elapsed == 0) {
-        return count;
+        return static_cast<double>(count);
     }
 
     return static_cast<double>(count) / elapsed;
@@ -115,4 +115,3 @@ uint64_t progress_display_t::overall_time(std::time_t now) const noexcept
 {
     return static_cast<uint64_t>(now - m_node.start);
 }
-
diff --git a/src/tagtransform-lua.cpp b/src/tagtransform-lua.cpp
index 814d9953e..386e8ed90 100644
--- a/src/tagtransform-lua.cpp
+++ b/src/tagtransform-lua.cpp
@@ -186,12 +186,12 @@ bool lua_tagtransform_t::filter_rel_member_tags(
     lua_newtable(lua_state()); /* member roles table */
 
     for (size_t i = 0; i < num_members; ++i) {
-        lua_pushnumber(lua_state(), i + 1);
+        lua_pushnumber(lua_state(), static_cast<lua_Number>(i + 1));
         lua_pushstring(lua_state(), member_roles[i]);
         lua_rawset(lua_state(), -3);
     }
 
-    lua_pushnumber(lua_state(), num_members);
+    lua_pushnumber(lua_state(), static_cast<lua_Number>(num_members));
 
     if (lua_pcall(lua_state(), 4, 6, 0)) {
         /* lua function failed */
diff --git a/src/util.hpp b/src/util.hpp
index 4ecf5bd69..7764a7fd4 100644
--- a/src/util.hpp
+++ b/src/util.hpp
@@ -109,7 +109,7 @@ class timer_t
      *
      * Returns 0 if the elapsed time is 0.
      */
-    double per_second(double value) const noexcept
+    double per_second(std::size_t value) const noexcept
     {
         auto const seconds =
             std::chrono::duration_cast<std::chrono::seconds>(m_duration)
@@ -117,7 +117,7 @@ class timer_t
         if (seconds == 0) {
             return 0.0;
         }
-        return value / static_cast<double>(seconds);
+        return static_cast<double>(value) / static_cast<double>(seconds);
     }
 
 private:
diff --git a/src/wkb.cpp b/src/wkb.cpp
index 239343414..17644067f 100644
--- a/src/wkb.cpp
+++ b/src/wkb.cpp
@@ -309,7 +309,8 @@ class ewkb_parser_t
 {
 public:
     ewkb_parser_t(char const *it, char const *end)
-    : m_it(it), m_end(end), m_max_length((end - it) / (sizeof(double) * 2))
+    : m_it(it), m_end(end),
+      m_max_length(static_cast<uint32_t>(end - it) / (sizeof(double) * 2))
     {}
 
     geom::geometry_t operator()()
diff --git a/tests/test-parse-osmium.cpp b/tests/test-parse-osmium.cpp
index 93af5405e..c8a8a8c97 100644
--- a/tests/test-parse-osmium.cpp
+++ b/tests/test-parse-osmium.cpp
@@ -124,8 +124,8 @@ struct counting_output_t : public output_null_t
 
     type_stats_t node, way, relation;
     long long sum_ids = 0;
-    unsigned sum_nds = 0;
-    unsigned sum_members = 0;
+    std::size_t sum_nds = 0;
+    std::size_t sum_members = 0;
 };
 
 struct counts_t {