diff --git a/components/apimgt/org.wso2.carbon.apimgt.gateway/src/main/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticator.java b/components/apimgt/org.wso2.carbon.apimgt.gateway/src/main/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticator.java
index e711a2cb5958..c69bbe0580cf 100644
--- a/components/apimgt/org.wso2.carbon.apimgt.gateway/src/main/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticator.java
+++ b/components/apimgt/org.wso2.carbon.apimgt.gateway/src/main/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticator.java
@@ -21,6 +21,7 @@
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.http.HttpHeaders;
 import org.apache.synapse.MessageContext;
 import org.apache.synapse.core.SynapseEnvironment;
 import org.apache.synapse.core.axis2.Axis2MessageContext;
@@ -368,6 +369,9 @@ public String getSecurityHeader() {
         if (this.securityHeader == null) {
             try {
                 securityHeader = APIUtil.getOAuthConfigurationFromAPIMConfig(APIConstants.AUTHORIZATION_HEADER);
+                if (securityHeader == null) {
+                    securityHeader = HttpHeaders.AUTHORIZATION;
+                }
             } catch (APIManagementException e) {
                 log.error("Error while reading authorization header from APIM configurations", e);
             }
diff --git a/components/apimgt/org.wso2.carbon.apimgt.gateway/src/test/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticatorTest.java b/components/apimgt/org.wso2.carbon.apimgt.gateway/src/test/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticatorTest.java
index 6c3215926e6c..569201f48626 100644
--- a/components/apimgt/org.wso2.carbon.apimgt.gateway/src/test/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticatorTest.java
+++ b/components/apimgt/org.wso2.carbon.apimgt.gateway/src/test/java/org/wso2/carbon/apimgt/gateway/handlers/security/basicauth/BasicAuthAuthenticatorTest.java
@@ -17,6 +17,7 @@
 package org.wso2.carbon.apimgt.gateway.handlers.security.basicauth;
 
 import io.swagger.v3.oas.models.OpenAPI;
+import org.apache.http.HttpHeaders;
 import org.apache.synapse.MessageContext;
 import org.apache.synapse.core.axis2.Axis2MessageContext;
 import org.junit.Assert;
@@ -36,12 +37,13 @@
 import org.wso2.carbon.apimgt.impl.APIManagerConfiguration;
 import org.wso2.carbon.apimgt.impl.dto.BasicAuthValidationInfoDTO;
 import org.wso2.carbon.apimgt.gateway.internal.ServiceReferenceHolder;
+import org.wso2.carbon.apimgt.impl.utils.APIUtil;
 
 import java.util.TreeMap;
 
 @RunWith(PowerMockRunner.class)
 @PrepareForTest({OpenAPIUtils.class, BasicAuthAuthenticator.class, BasicAuthCredentialValidator.class,
-        ServiceReferenceHolder.class})
+        ServiceReferenceHolder.class, APIUtil.class})
 public class BasicAuthAuthenticatorTest {
     private MessageContext messageContext;
     private org.apache.axis2.context.MessageContext axis2MsgCntxt;
@@ -53,6 +55,7 @@ public class BasicAuthAuthenticatorTest {
     @Before
     public void setup() throws Exception {
         PowerMockito.mockStatic(OpenAPIUtils.class);
+        PowerMockito.mockStatic(APIUtil.class);
         PowerMockito.when(OpenAPIUtils.getResourceAuthenticationScheme(Mockito.any(), Mockito.any()))
                 .thenReturn(APIConstants.AUTH_APPLICATION_OR_USER_LEVEL_TOKEN);
 
@@ -207,4 +210,16 @@ public void testAuthenticateWithRemoveOAuthHeadersFromOutMessageSetToFalse() {
         Assert.assertNotNull(transportHeaders.get(CUSTOM_AUTH_HEADER));
         Assert.assertEquals(transportHeaders.get(CUSTOM_AUTH_HEADER), "Basic dGVzdF91c2VybmFtZTp0ZXN0X3Bhc3N3b3Jk");
     }
+
+    /**
+     * Test case for getSecurityHeader method when security header is null
+     * The null should be handled and HttpHeaders.AUTHORIZATION should be returned
+     */
+    @Test public void testSetSecurityHeaderWithNullHeader() throws Exception {
+        PowerMockito.when(APIUtil.getOAuthConfigurationFromAPIMConfig(Mockito.anyString())).thenReturn(null);
+        BasicAuthAuthenticator basicAuthAuthenticatorWithNullHeader = new BasicAuthAuthenticator(null, true,
+                UNLIMITED_THROTTLE_POLICY);
+        String actualHeader = basicAuthAuthenticatorWithNullHeader.getSecurityHeader();
+        Assert.assertEquals(HttpHeaders.AUTHORIZATION, actualHeader);
+    }
 }
\ No newline at end of file