diff --git a/src/silo/preprocessing/sequence_info.cpp b/src/silo/preprocessing/sequence_info.cpp
index a4e6f93cf..32ed47ee9 100644
--- a/src/silo/preprocessing/sequence_info.cpp
+++ b/src/silo/preprocessing/sequence_info.cpp
@@ -71,6 +71,7 @@ std::string SequenceInfo::getAminoAcidSequenceSelect(
    );
 }
 
+namespace {
 void validateStruct(
    std::vector<std::string> names_to_validate,
    std::vector<std::string> names_to_validate_against,
@@ -101,6 +102,7 @@ void validateStruct(
       }
    }
 }
+}  // namespace
 
 void SequenceInfo::validateNdjsonFile(
    const silo::ReferenceGenomes& reference_genomes,
diff --git a/src/silo/query_engine/actions/action.cpp b/src/silo/query_engine/actions/action.cpp
index 12cb6bd54..675fc0ceb 100644
--- a/src/silo/query_engine/actions/action.cpp
+++ b/src/silo/query_engine/actions/action.cpp
@@ -29,13 +29,6 @@ namespace silo::query_engine::actions {
 
 Action::Action() = default;
 
-std::string stringToLowerCase(std::string str) {
-   std::transform(str.begin(), str.end(), str.begin(), [](unsigned char character) {
-      return std::tolower(character);
-   });
-   return str;
-}
-
 void Action::applySort(QueryResult& result) const {
    auto& result_vector = result.query_result;
 
@@ -126,7 +119,7 @@ QueryResult Action::executeAndOrder(
    return result;
 }
 
-// NOLINTNEXTLINE(readability-identifier-naming)
+// NOLINTNEXTLINE(readability-identifier-naming,misc-use-internal-linkage)
 void from_json(const nlohmann::json& json, OrderByField& field) {
    if (json.is_string()) {
       field = {.name = json.get<std::string>(), .ascending = true};
diff --git a/src/silo/test/int_equals_and_between.test.cpp b/src/silo/test/int_equals_and_between.test.cpp
index d76f8c34b..dbe58c2d4 100644
--- a/src/silo/test/int_equals_and_between.test.cpp
+++ b/src/silo/test/int_equals_and_between.test.cpp
@@ -4,17 +4,18 @@
 
 #include "silo/test/query_fixture.test.h"
 
+namespace {
 using silo::ReferenceGenomes;
 using silo::config::DatabaseConfig;
 using silo::config::ValueType;
 using silo::test::QueryTestData;
 using silo::test::QueryTestScenario;
 
-static const int VALUE_IN_FILTER = 3;
-static const int VALUE_BELOW_FILTER = 1;
-static const int VALUE_ABOVE_FILTER = 5;
-static const int BELOW_FILTER = 2;
-static const int ABOVE_FILTER = 4;
+const int VALUE_IN_FILTER = 3;
+const int VALUE_BELOW_FILTER = 1;
+const int VALUE_ABOVE_FILTER = 5;
+const int BELOW_FILTER = 2;
+const int ABOVE_FILTER = 4;
 
 nlohmann::json createDataWithIntValue(const std::string& primaryKey, int value) {
    return {
@@ -140,6 +141,7 @@ const QueryTestScenario INT_BETWEEN_WITH_FROM_AND_TO_NULL_SCENARIO = {
        {{"primaryKey", "id_3"}, {"int_value", VALUE_ABOVE_FILTER}}}
    )
 };
+}  // namespace
 
 QUERY_TEST(
    IntEqualsTest,