diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/DirectedTypeScriptCodegen.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/DirectedTypeScriptCodegen.java
index 3a4d1c1b1b5..f70ab9cc58b 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/DirectedTypeScriptCodegen.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/DirectedTypeScriptCodegen.java
@@ -56,6 +56,7 @@
 import software.amazon.smithy.typescript.codegen.integration.RuntimeClientPlugin;
 import software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration;
 import software.amazon.smithy.typescript.codegen.validation.LongValidator;
+import software.amazon.smithy.typescript.codegen.validation.ReplaceLast;
 import software.amazon.smithy.utils.MapUtils;
 import software.amazon.smithy.utils.SmithyUnstableApi;
 import software.amazon.smithy.waiters.WaitableTrait;
@@ -249,8 +250,8 @@ private void generateClient(GenerateServiceDirective<TypeScriptCodegenContext, T
 
         // Generate the aggregated service client.
         Symbol serviceSymbol = symbolProvider.toSymbol(service);
-        String aggregatedClientName = serviceSymbol.getName().replace("Client", "");
-        String filename = serviceSymbol.getDefinitionFile().replace("Client", "");
+        String aggregatedClientName = ReplaceLast.in(serviceSymbol.getName(), "Client", "");
+        String filename = ReplaceLast.in(serviceSymbol.getDefinitionFile(), "Client", "");
         delegator.useFileWriter(filename, writer -> new ServiceAggregatedClientGenerator(
                 settings, model, symbolProvider, aggregatedClientName, writer, applicationProtocol).run());
 
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/ExtensionConfigurationGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/ExtensionConfigurationGenerator.java
index f8acb3765fb..a35a4fd20b8 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/ExtensionConfigurationGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/ExtensionConfigurationGenerator.java
@@ -23,6 +23,7 @@
 import software.amazon.smithy.model.Model;
 import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration;
+import software.amazon.smithy.typescript.codegen.validation.ReplaceLast;
 
 public class ExtensionConfigurationGenerator {
 
@@ -62,9 +63,13 @@ void generate() {
             });
         }
 
-        String clientName = symbolProvider.toSymbol(service).getName()
-                .replace("Client", "")
-                .replace("client", "");
+        String clientName = ReplaceLast.in(
+            ReplaceLast.in(
+                symbolProvider.toSymbol(service).getName(),
+                "Client", ""
+            ),
+            "client", ""
+        );
 
         String clientConfigurationContent = TypeScriptUtils
             .loadResourceAsString(CLIENT_CONFIGURATION_TEMPLATE)
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/IndexGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/IndexGenerator.java
index 34db6baf84d..46b4d8017fd 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/IndexGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/IndexGenerator.java
@@ -29,6 +29,7 @@
 import software.amazon.smithy.model.traits.PaginatedTrait;
 import software.amazon.smithy.rulesengine.traits.EndpointRuleSetTrait;
 import software.amazon.smithy.typescript.codegen.integration.ProtocolGenerator;
+import software.amazon.smithy.typescript.codegen.validation.ReplaceLast;
 import software.amazon.smithy.utils.SmithyInternalApi;
 import software.amazon.smithy.waiters.WaitableTrait;
 
@@ -99,7 +100,7 @@ private static void writeClientExports(
         ServiceShape service = settings.getService(model);
         Symbol symbol = symbolProvider.toSymbol(service);
         // Normalizes client name, e.g. WeatherClient => Weather
-        String normalizedClientName = symbol.getName().replace("Client", "");
+        String normalizedClientName = ReplaceLast.in(symbol.getName(), "Client", "");
 
         // Write export statement for bare-bones client.
         writer.write("export * from \"./$L\";", symbol.getName());
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/RuntimeExtensionsGenerator.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/RuntimeExtensionsGenerator.java
index 9bd063f2e9e..03b37c5c348 100644
--- a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/RuntimeExtensionsGenerator.java
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/RuntimeExtensionsGenerator.java
@@ -21,6 +21,7 @@
 import software.amazon.smithy.model.Model;
 import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration;
+import software.amazon.smithy.typescript.codegen.validation.ReplaceLast;
 
 public class RuntimeExtensionsGenerator {
 
@@ -52,9 +53,13 @@ public RuntimeExtensionsGenerator(
     }
 
     void generate() {
-        String clientName = symbolProvider.toSymbol(service).getName()
-                .replace("Client", "")
-                .replace("client", "");
+        String clientName = ReplaceLast.in(
+            ReplaceLast.in(
+                symbolProvider.toSymbol(service).getName(),
+                "Client", ""
+            ),
+            "client", ""
+        );
 
         String template1Contents = TypeScriptUtils.loadResourceAsString(TEMPLATE_1)
             .replace("${extensionConfigName}", clientName + "ExtensionConfiguration")
diff --git a/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/validation/ReplaceLast.java b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/validation/ReplaceLast.java
new file mode 100644
index 00000000000..a7add557c6f
--- /dev/null
+++ b/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/validation/ReplaceLast.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.smithy.typescript.codegen.validation;
+
+public abstract class ReplaceLast {
+
+    /**
+     * @param original - source string.
+     * @param target - substring to be replaced.
+     * @param replacement - the replacement.
+     * @return original with the last occurrence of the target string replaced by the replacement string.
+     */
+    public static String in(String original, String target, String replacement) {
+        int lastPosition = original.lastIndexOf(target);
+        if (lastPosition >= 0) {
+            return original.substring(0, lastPosition)
+                + replacement
+                + original.substring(lastPosition + target.length());
+        }
+        return original;
+    }
+}
diff --git a/smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/validation/ReplaceLastTest.java b/smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/validation/ReplaceLastTest.java
new file mode 100644
index 00000000000..eaa5152f3a0
--- /dev/null
+++ b/smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/validation/ReplaceLastTest.java
@@ -0,0 +1,16 @@
+package software.amazon.smithy.typescript.codegen.validation;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ReplaceLastTest {
+
+    @Test
+    public void replaceLast() {
+        assertEquals(ReplaceLast.in("WorkspacesThinClientClient", "Client", ""), "WorkspacesThinClient");
+        assertEquals(ReplaceLast.in("WorkspacesThinClientClientClient", "Client", ""), "WorkspacesThinClientClient");
+
+        assertEquals(ReplaceLast.in("welcometothecity", "e", "is"), "welcometothiscity");
+    }
+}
\ No newline at end of file