diff --git a/src/internal/reader_common.h b/src/internal/reader_common.h
index 7c84f1f9..09815d01 100644
--- a/src/internal/reader_common.h
+++ b/src/internal/reader_common.h
@@ -13,9 +13,18 @@ Value jsonToValue(nlohmann::json value)
 {
     if (value.is_string())
         return value.get<std::string>();
-    else if (value.is_number())
-        return std::stod(value.dump());
-    else if (value.is_boolean())
+    else if (value.is_number()) {
+        // Set locale to C to avoid conversion issues
+        std::string oldLocale = std::setlocale(LC_NUMERIC, nullptr);
+        std::setlocale(LC_NUMERIC, "C");
+
+        double converted = std::stod(value.dump());
+
+        // Restore old locale
+        std::setlocale(LC_NUMERIC, oldLocale.c_str());
+
+        return converted;
+    } else if (value.is_boolean())
         return value.get<bool>();
     else
         return value.dump();
diff --git a/test/load_project/load_project_test.cpp b/test/load_project/load_project_test.cpp
index 639e4c0d..55ffce39 100644
--- a/test/load_project/load_project_test.cpp
+++ b/test/load_project/load_project_test.cpp
@@ -709,3 +709,21 @@ TEST(LoadProjectTest, LoadNullDimensionMonitor)
     Project p(name);
     ASSERT_TRUE(p.load());
 }
+
+TEST(LoadProjectTest, LoadDoubleValue)
+{
+    // Regtest for #437
+    std::string oldLocale = std::setlocale(LC_NUMERIC, nullptr);
+    std::setlocale(LC_NUMERIC, "sk_SK.UTF-8");
+
+    std::string name = "regtest_projects/437_load_double_values.sb3";
+    Project p(name);
+    ASSERT_TRUE(p.load());
+
+    auto stage = p.engine()->stage();
+    ASSERT_TRUE(stage);
+    ASSERT_VAR(stage, "test");
+    ASSERT_EQ(GET_VAR(stage, "test")->value().toDouble(), 5.6654);
+
+    std::setlocale(LC_NUMERIC, oldLocale.c_str());
+}
diff --git a/test/regtest_projects/437_load_double_values.sb3 b/test/regtest_projects/437_load_double_values.sb3
new file mode 100644
index 00000000..918a7ae1
Binary files /dev/null and b/test/regtest_projects/437_load_double_values.sb3 differ