diff --git a/airbyte-integrations/connectors/source-jdbc/src/main/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSource.java b/airbyte-integrations/connectors/source-jdbc/src/main/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSource.java
index fa390578dcb4..ea58d1cb0108 100644
--- a/airbyte-integrations/connectors/source-jdbc/src/main/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSource.java
+++ b/airbyte-integrations/connectors/source-jdbc/src/main/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSource.java
@@ -299,7 +299,7 @@ protected DataSource createDataSource(final JsonNode config) {
         jdbcConfig.has(JdbcUtils.PASSWORD_KEY) ? jdbcConfig.get(JdbcUtils.PASSWORD_KEY).asText() : null,
         driverClass,
         jdbcConfig.get(JdbcUtils.JDBC_URL_KEY).asText(),
-        JdbcUtils.parseJdbcParameters(jdbcConfig, JdbcUtils.CONNECTION_PROPERTIES_KEY, getJdbcParameterDelimiter()));
+        getConnectionProperties(config));
     // Record the data source so that it can be closed.
     dataSources.add(dataSource);
     return dataSource;
@@ -339,7 +339,7 @@ protected Map<String, String> getConnectionProperties(final JsonNode config) {
    * @param defaultParameters connection properties map as specified by each Jdbc source
    * @throws IllegalArgumentException
    */
-  private void assertCustomParametersDontOverwriteDefaultParameters(final Map<String, String> customParameters,
+  protected static void assertCustomParametersDontOverwriteDefaultParameters(final Map<String, String> customParameters,
                                                                     final Map<String, String> defaultParameters) {
     for (final String key : defaultParameters.keySet()) {
       if (customParameters.containsKey(key) && !Objects.equals(customParameters.get(key), defaultParameters.get(key))) {
diff --git a/airbyte-integrations/connectors/source-jdbc/src/test/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSourceAcceptanceTest.java b/airbyte-integrations/connectors/source-jdbc/src/test/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSourceAcceptanceTest.java
index 5f690f08db38..1e5eea3bbcaf 100644
--- a/airbyte-integrations/connectors/source-jdbc/src/test/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSourceAcceptanceTest.java
+++ b/airbyte-integrations/connectors/source-jdbc/src/test/java/io/airbyte/integrations/source/jdbc/AbstractJdbcSourceAcceptanceTest.java
@@ -4,6 +4,9 @@
 
 package io.airbyte.integrations.source.jdbc;
 
+import static io.airbyte.integrations.source.jdbc.AbstractJdbcSource.assertCustomParametersDontOverwriteDefaultParameters;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import com.fasterxml.jackson.databind.JsonNode;
 import com.google.common.collect.ImmutableMap;
 import io.airbyte.commons.features.EnvVariableFeatureFlags;
@@ -22,12 +25,16 @@
 import io.airbyte.protocol.models.AirbyteStateMessage.AirbyteStateType;
 import io.airbyte.protocol.models.AirbyteStreamState;
 import io.airbyte.test.utils.PostgreSQLContainerHelper;
+import io.airbyte.integrations.util.HostPortResolver;
 import java.sql.JDBCType;
 import java.util.List;
+import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.testcontainers.containers.PostgreSQLContainer;
@@ -43,6 +50,7 @@ class AbstractJdbcSourceAcceptanceTest extends JdbcSourceAcceptanceTest {
   private static PostgreSQLContainer<?> PSQL_DB;
 
   private JsonNode config;
+  private String dbName;
 
   @BeforeAll
   static void init() {
@@ -53,7 +61,7 @@ static void init() {
 
   @BeforeEach
   public void setup() throws Exception {
-    final String dbName = Strings.addRandomSuffix("db", "_", 10).toLowerCase();
+    dbName = Strings.addRandomSuffix("db", "_", 10).toLowerCase();
 
     config = Jsons.jsonNode(ImmutableMap.builder()
         .put(JdbcUtils.HOST_KEY, PSQL_DB.getHost())
@@ -85,6 +93,18 @@ public JsonNode getConfig() {
     return config;
   }
 
+  public JsonNode getConfigWithConnectionProperties(final PostgreSQLContainer<?> psqlDb, final String dbName, final String additionalParameters) {
+    return Jsons.jsonNode(ImmutableMap.builder()
+        .put(JdbcUtils.HOST_KEY, HostPortResolver.resolveHost(psqlDb))
+        .put(JdbcUtils.PORT_KEY, HostPortResolver.resolvePort(psqlDb))
+        .put(JdbcUtils.DATABASE_KEY, dbName)
+        .put(JdbcUtils.SCHEMAS_KEY, List.of(SCHEMA_NAME))
+        .put(JdbcUtils.USERNAME_KEY, psqlDb.getUsername())
+        .put(JdbcUtils.PASSWORD_KEY, psqlDb.getPassword())
+        .put(JdbcUtils.CONNECTION_PROPERTIES_KEY, additionalParameters)
+        .build());
+  }
+
   @Override
   public String getDriverClass() {
     return PostgresTestSource.DRIVER_CLASS;
@@ -161,4 +181,18 @@ public static void main(final String[] args) throws Exception {
 
   }
 
+  @Test
+  void testCustomParametersOverwriteDefaultParametersExpectException() {
+    final String connectionPropertiesUrl = "ssl=false";
+    final JsonNode config = getConfigWithConnectionProperties(PSQL_DB, dbName, connectionPropertiesUrl);
+    final Map<String, String> customParameters = JdbcUtils.parseJdbcParameters(config, JdbcUtils.CONNECTION_PROPERTIES_KEY, "&");
+    final Map<String, String> defaultParameters = Map.of(
+        "ssl", "true",
+        "sslmode", "require"
+    );
+    assertThrows(IllegalArgumentException.class, () -> {
+      assertCustomParametersDontOverwriteDefaultParameters(customParameters, defaultParameters);
+    });
+  }
+
 }
diff --git a/airbyte-integrations/connectors/source-postgres/src/main/java/io/airbyte/integrations/source/postgres/PostgresSource.java b/airbyte-integrations/connectors/source-postgres/src/main/java/io/airbyte/integrations/source/postgres/PostgresSource.java
index d0ebab199c30..a8da51ae7d4d 100644
--- a/airbyte-integrations/connectors/source-postgres/src/main/java/io/airbyte/integrations/source/postgres/PostgresSource.java
+++ b/airbyte-integrations/connectors/source-postgres/src/main/java/io/airbyte/integrations/source/postgres/PostgresSource.java
@@ -72,15 +72,6 @@
 public class PostgresSource extends AbstractJdbcSource<JDBCType> implements Source {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(PostgresSource.class);
-
-  public static final String CDC_LSN = "_ab_cdc_lsn";
-  public static final String DATABASE_KEY = "database";
-  public static final String HOST_KEY = "host";
-  public static final String JDBC_URL_KEY = "jdbc_url";
-  public static final String PASSWORD_KEY = "password";
-  public static final String PORT_KEY = "port";
-  public static final String SCHEMAS_KEY = "schemas";
-  public static final String USERNAME_KEY = "username";
   static final String DRIVER_CLASS = DatabaseDriver.POSTGRESQL.getDriverClassName();
   static final Map<String, String> SSL_JDBC_PARAMETERS = ImmutableMap.of(
       "ssl", "true",