diff --git a/CHANGELOG.md b/CHANGELOG.md
index 463e9401..bad5c336 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [9.4.1]
 
+- Fixes env var reading with specific types
 - Updates dependencies for testing
 
 ## [9.4.0]
diff --git a/build.gradle b/build.gradle
index f1cc9f0a..5251cbe7 100644
--- a/build.gradle
+++ b/build.gradle
@@ -82,7 +82,8 @@ tasks.register('generateMetaInf') {
 build.dependsOn(generateMetaInf)
 
 test {
-    jvmArgs '-Djava.security.egd=file:/dev/urandom'
+    jvmArgs '-Djava.security.egd=file:/dev/urandom',
+            '--add-opens=java.base/java.util=ALL-UNNAMED'
     minHeapSize = "128m" // initial heap size
     maxHeapSize = "1024m" // maximum heap size
     testLogging {
diff --git a/src/main/java/io/supertokens/storage/postgresql/Start.java b/src/main/java/io/supertokens/storage/postgresql/Start.java
index 28cea0ee..3981bf69 100644
--- a/src/main/java/io/supertokens/storage/postgresql/Start.java
+++ b/src/main/java/io/supertokens/storage/postgresql/Start.java
@@ -863,18 +863,24 @@ public void updateConfigJsonFromEnv(JsonObject configJson) {
                             .replace("\\\\", "\\");
                 }
 
+                // Empty/unset stringValue is already handled above (null/empty check),
+                // so boxed types (Integer, Long, etc.) can safely share branches
+                // with their primitive counterparts.
                 if (field.getType().equals(String.class)) {
                     configJson.addProperty(field.getName(), stringValue);
-                } else if (field.getType().equals(int.class)) {
+                } else if (field.getType().equals(int.class) || field.getType().equals(Integer.class)) {
                     configJson.addProperty(field.getName(), Integer.parseInt(stringValue));
-                } else if (field.getType().equals(long.class)) {
+                } else if (field.getType().equals(long.class) || field.getType().equals(Long.class)) {
                     configJson.addProperty(field.getName(), Long.parseLong(stringValue));
-                } else if (field.getType().equals(boolean.class)) {
+                } else if (field.getType().equals(boolean.class) || field.getType().equals(Boolean.class)) {
                     configJson.addProperty(field.getName(), Boolean.parseBoolean(stringValue));
-                } else if (field.getType().equals(float.class)) {
+                } else if (field.getType().equals(float.class) || field.getType().equals(Float.class)) {
                     configJson.addProperty(field.getName(), Float.parseFloat(stringValue));
-                } else if (field.getType().equals(double.class)) {
+                } else if (field.getType().equals(double.class) || field.getType().equals(Double.class)) {
                     configJson.addProperty(field.getName(), Double.parseDouble(stringValue));
+                } else {
+                    throw new RuntimeException(
+                            "Unknown field type " + field.getType().getName() + " for config field " + field.getName());
                 }
             }
         }
diff --git a/src/test/java/io/supertokens/storage/postgresql/test/EnvConfigTest.java b/src/test/java/io/supertokens/storage/postgresql/test/EnvConfigTest.java
new file mode 100644
index 00000000..28e72fd3
--- /dev/null
+++ b/src/test/java/io/supertokens/storage/postgresql/test/EnvConfigTest.java
@@ -0,0 +1,95 @@
+/*
+ *    Copyright (c) 2025, VRAI Labs and/or its affiliates. All rights reserved.
+ *
+ *    This software is licensed under the Apache License, Version 2.0 (the
+ *    "License") as published by the Apache Software Foundation.
+ *
+ *    You may not use this file except in compliance with the License. You may
+ *    obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ *    License for the specific language governing permissions and limitations
+ *    under the License.
+ */
+
+package io.supertokens.storage.postgresql.test;
+
+import com.google.gson.JsonObject;
+import io.supertokens.storage.postgresql.Start;
+import org.junit.Test;
+
+import java.lang.reflect.Field;
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+public class EnvConfigTest {
+
+    private static void setEnv(String key, String value) {
+        try {
+            Map<String, String> env = System.getenv();
+            Class<?> cl = env.getClass();
+            Field field = cl.getDeclaredField("m");
+            field.setAccessible(true);
+            @SuppressWarnings("unchecked")
+            Map<String, String> writableEnv = (Map<String, String>) field.get(env);
+            writableEnv.put(key, value);
+        } catch (Exception e) {
+            throw new IllegalStateException("Failed to set environment variable", e);
+        }
+    }
+
+    private static void removeEnv(String key) {
+        try {
+            Map<String, String> env = System.getenv();
+            Class<?> cl = env.getClass();
+            Field field = cl.getDeclaredField("m");
+            field.setAccessible(true);
+            @SuppressWarnings("unchecked")
+            Map<String, String> writableEnv = (Map<String, String>) field.get(env);
+            writableEnv.remove(key);
+        } catch (Exception e) {
+            throw new IllegalStateException("Failed to remove environment variable", e);
+        }
+    }
+
+    @Test
+    public void testUpdateConfigJsonFromEnvHandlesBoxedTypes() {
+        // Regression test: Integer fields like postgresql_minimum_idle_connections
+        // were silently dropped because updateConfigJsonFromEnv only checked
+        // primitive types (int.class) not boxed types (Integer.class).
+        Start start = new Start();
+        try {
+            setEnv("POSTGRESQL_MINIMUM_IDLE_CONNECTIONS", "5");
+
+            JsonObject configJson = new JsonObject();
+            start.updateConfigJsonFromEnv(configJson);
+
+            assertTrue("POSTGRESQL_MINIMUM_IDLE_CONNECTIONS env var should be loaded into configJson",
+                    configJson.has("postgresql_minimum_idle_connections"));
+            assertEquals(5, configJson.get("postgresql_minimum_idle_connections").getAsInt());
+        } finally {
+            removeEnv("POSTGRESQL_MINIMUM_IDLE_CONNECTIONS");
+        }
+    }
+
+    @Test
+    public void testUpdateConfigJsonFromEnvHandlesBoxedTypeWithZero() {
+        // Tests that Integer value of 0 is correctly loaded (not confused with null/unset)
+        Start start = new Start();
+        try {
+            setEnv("POSTGRESQL_MINIMUM_IDLE_CONNECTIONS", "0");
+
+            JsonObject configJson = new JsonObject();
+            start.updateConfigJsonFromEnv(configJson);
+
+            assertTrue("POSTGRESQL_MINIMUM_IDLE_CONNECTIONS env var with value 0 should be loaded",
+                    configJson.has("postgresql_minimum_idle_connections"));
+            assertEquals(0, configJson.get("postgresql_minimum_idle_connections").getAsInt());
+        } finally {
+            removeEnv("POSTGRESQL_MINIMUM_IDLE_CONNECTIONS");
+        }
+    }
+}