diff --git a/app/server/appsmith-server/src/main/java/com/appsmith/server/services/ActionServiceImpl.java b/app/server/appsmith-server/src/main/java/com/appsmith/server/services/ActionServiceImpl.java
index 3d36a16020..0f35f16242 100644
--- a/app/server/appsmith-server/src/main/java/com/appsmith/server/services/ActionServiceImpl.java
+++ b/app/server/appsmith-server/src/main/java/com/appsmith/server/services/ActionServiceImpl.java
@@ -36,6 +36,7 @@ import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.stereotype.Service;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.LinkedCaseInsensitiveMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
 import reactor.core.publisher.Flux;
@@ -51,8 +52,10 @@ import java.io.UnsupportedEncodingException;
 import java.io.Writer;
 import java.net.URLDecoder;
 import java.time.Duration;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -252,12 +255,11 @@ public class ActionServiceImpl extends BaseService<ActionRepository, Action, Str
         }
 
         if (actionConfiguration.getHeaders() != null) {
-            Map<String, String> reqHeaderMap = actionConfiguration.getHeaders().stream()
-                    .collect(Collectors.toMap(Property::getKey,
-                            Property::getValue,
-                            // If there are duplicate values, ignore the second one
-                            (header1, header2) -> header1));
-            actionExecutionResult.setRequestHeaders(objectMapper.valueToTree(reqHeaderMap));
+            MultiValueMap<String, String> reqMultiMap = CollectionUtils.toMultiValueMap(new LinkedCaseInsensitiveMap<>(8, Locale.ENGLISH));
+
+            actionConfiguration.getHeaders().stream()
+                    .forEach(header -> reqMultiMap.put(header.getKey(), Arrays.asList(header.getValue())));
+            actionExecutionResult.setRequestHeaders(objectMapper.valueToTree(reqMultiMap));
             log.debug("Got request headers in actionExecutionResult as: {}", actionExecutionResult.getRequestHeaders());
         }
 
diff --git a/app/server/appsmith-server/src/test/java/com/appsmith/server/services/ActionServiceTest.java b/app/server/appsmith-server/src/test/java/com/appsmith/server/services/ActionServiceTest.java
index 4c56f9655c..2bfa767d4c 100644
--- a/app/server/appsmith-server/src/test/java/com/appsmith/server/services/ActionServiceTest.java
+++ b/app/server/appsmith-server/src/test/java/com/appsmith/server/services/ActionServiceTest.java
@@ -22,9 +22,12 @@ import org.springframework.http.HttpMethod;
 import org.springframework.security.test.context.support.WithUserDetails;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.util.CollectionUtils;
+import org.springframework.util.MultiValueMap;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -246,7 +249,7 @@ public class ActionServiceTest {
         actionConfiguration.setHeaders(List.of(
                 new Property("random-header-key", "random-header-value"),
                 new Property("dup-key", "dup-value1"),
-                new Property("dup-key", "dup-value2")
+                new Property("DUP-key", "dup-value2")
         ));
         action.setActionConfiguration(actionConfiguration);
 
@@ -256,9 +259,11 @@ public class ActionServiceTest {
         Mono<ActionExecutionResult> executionResultMono = executeAction(executeActionDTO, actionConfiguration, mockResult);
         StepVerifier.create(executionResultMono)
                 .assertNext(result -> {
-                    // The fxn should have ignored all duplicate headers
+                    // Assert that the fxn should pick up the latest key based on the case-insensitive values
                     assertThat(result.getRequestHeaders().size()).isEqualTo(2);
-                    Map<String, String> resultHeader = Map.of("random-header-key", "random-header-value", "dup-key", "dup-value1");
+                    MultiValueMap<String, String> resultHeader = CollectionUtils.toMultiValueMap(Map.of(
+                            "random-header-key", Arrays.asList("random-header-value"),
+                            "DUP-key", Arrays.asList("dup-value2")));
                     assertThat(result.getRequestHeaders()).isEqualTo(objectMapper.valueToTree(resultHeader));
                 })
                 .verifyComplete();
@@ -288,7 +293,9 @@ public class ActionServiceTest {
                 .assertNext(result -> {
                     // The fxn should have ignored all duplicate headers
                     assertThat(result.getRequestHeaders().size()).isEqualTo(1);
-                    Map<String, String> resultHeader = Map.of("random-header-key", "random-header-value");
+                    MultiValueMap<String, String> resultHeader = CollectionUtils.toMultiValueMap(Map.of(
+                            "random-header-key", Arrays.asList("random-header-value")));
+
                     assertThat(result.getRequestHeaders()).isEqualTo(objectMapper.valueToTree(resultHeader));
                 })
                 .verifyComplete();