diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java
index 8bb617172e2..7858de905a3 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpBindingProtocolGenerator.java
@@ -227,16 +227,21 @@ private void generateOperationSerializer(
                 HttpProtocolGeneratorUtils.writeHostPrefix(context, operation);
             }
 
+            // Get the hostname, port, and scheme from client's resolved endpoint. Then construct the request from
+            // them. The client's resolved endpoint can be default one or supplied by users.
+            writer.write("const {hostname, protocol = \"https\", port} = await context.endpoint();");
             writer.openBlock("return new $T({", "});", requestType, () -> {
                 if (hasHostPrefix) {
                     writer.write("hostname: resolvedHostname,");
                 }
-                writer.write("protocol: \"https\",");
+                writer.write("protocol,");
+                writer.write("hostname,");
+                writer.write("port,");
                 writer.write("method: $S,", trait.getMethod());
-                writer.write("headers: headers,");
+                writer.write("headers,");
                 writer.write("path: resolvedPath,");
                 if (hasQueryComponents) {
-                    writer.write("query: query,");
+                    writer.write("query,");
                 }
                 if (!bodyBindings.isEmpty()) {
                     // Track all shapes bound to the body so their serializers may be generated.
@@ -246,8 +251,7 @@ private void generateOperationSerializer(
                             .forEach(serializingDocumentShapes::add);
                 }
                 // Always set the body,
-                writer.write("body: body,");
-                writer.write("...context.endpoint,");
+                writer.write("body,");
             });
         });
 
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpRpcProtocolGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpRpcProtocolGenerator.java
index 8ff75bc339a..d12354f2c7e 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpRpcProtocolGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpRpcProtocolGenerator.java
@@ -100,19 +100,23 @@ public void generateSharedComponents(GenerationContext context) {
         writer.addUseImports(requestType);
         writer.addImport("SerdeContext", "__SerdeContext", "@aws-sdk/types");
         writer.addImport("HeaderBag", "__HeaderBag", "@aws-sdk/types");
-        writer.openBlock("const buildHttpRpcRequest = (\n"
+        writer.openBlock("const buildHttpRpcRequest = async (\n"
                        + "  context: __SerdeContext,\n"
                        + "  headers: __HeaderBag,\n"
                        + "  path: string,\n"
                        + "  resolvedHostname: string | undefined,\n"
                        + "  body: any,\n"
-                       + "): $T => {", "};", requestType, () -> {
+                       + "): Promise<$T> => {", "};", requestType, () -> {
+            // Get the hostname, port, and scheme from client's resolved endpoint. Then construct the request from
+            // them. The client's resolved endpoint can be default one or supplied by users.
+            writer.write("const {hostname, protocol = \"https\", port} = await context.endpoint();");
             writer.openBlock("const contents: any = {", "};", () -> {
-                writer.write("protocol: \"https\",");
+                writer.write("protocol,");
+                writer.write("hostname,");
+                writer.write("port,");
                 writer.write("method: \"POST\",");
-                writer.write("path: path,");
-                writer.write("headers: headers,");
-                writer.write("...context.endpoint,");
+                writer.write("path,");
+                writer.write("headers,");
             });
             writer.openBlock("if (resolvedHostname !== undefined) {", "}", () -> {
                 writer.write("contents.hostname = resolvedHostname;");