diff --git a/wsdef/pom.xml b/wsdef/pom.xml
index 8f43abdc..7515ac7a 100644
--- a/wsdef/pom.xml
+++ b/wsdef/pom.xml
@@ -64,14 +64,6 @@
       <scope>compile</scope>
     </dependency>
 
-    <!-- Guice: Dependency injection -->
-    <dependency>
-      <groupId>com.google.inject</groupId>
-      <artifactId>guice</artifactId>
-      <version>2.0</version>
-      <scope>compile</scope>
-    </dependency>
-
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/CallPathMap.java b/wsdef/src/main/java/com/google/gson/webservice/definition/CallPathMap.java
index 3ddf0524..c083f92a 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/CallPathMap.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/CallPathMap.java
@@ -15,10 +15,9 @@
  */
 package com.google.gson.webservice.definition;
 
+import java.util.HashMap;
 import java.util.Map;
 
-import com.google.common.collect.Maps;
-
 /**
  * A generic Map of calls with relative path where the call is available as the key. 
  * 
@@ -29,7 +28,7 @@ import com.google.common.collect.Maps;
 public final class CallPathMap<T> {
   
   public static class Builder<T> {
-    private final Map<CallPath, T> contents = Maps.newHashMap();
+    private final Map<CallPath, T> contents = new HashMap<CallPath, T>();
     private final T nullValue;
     
     public Builder(T nullValue) {
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMap.java b/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMap.java
index 948895c8..4ce3f048 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMap.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMap.java
@@ -18,8 +18,6 @@ package com.google.gson.webservice.definition;
 import java.lang.reflect.Type;
 import java.util.Map;
 
-import com.google.inject.Inject;
-
 /**
  * Map of request or response header objects. There is a {@link HeaderMapSpec} associated with the
  * map as well and only those headers are allowed that are consistent with the specification.
@@ -29,7 +27,6 @@ import com.google.inject.Inject;
 public final class HeaderMap extends ParamMap {
 
   public static class Builder extends ParamMap.Builder<HeaderMapSpec> {
-    @Inject
     public Builder(HeaderMapSpec spec) {
       super(spec);
     }
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMapSpec.java b/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMapSpec.java
index 91bc6e7e..154c9a6d 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMapSpec.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/HeaderMapSpec.java
@@ -16,11 +16,10 @@
 package com.google.gson.webservice.definition;
 
 import java.lang.reflect.Type;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
 
-import com.google.common.collect.Maps;
-
 /**
  * Specification of a header map for {@link HeaderMap}. 
  *
@@ -29,7 +28,7 @@ import com.google.common.collect.Maps;
 public final class HeaderMapSpec implements ParamMapSpec {
   
   public static class Builder {
-    private final Map<String, Type> map = Maps.newLinkedHashMap();
+    private final Map<String, Type> map = new LinkedHashMap<String, Type>();
   
     public void put(String headerName, Type headerType) {
       map.put(headerName, headerType);
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/ParamMap.java b/wsdef/src/main/java/com/google/gson/webservice/definition/ParamMap.java
index 5e7b141c..7f66cbf3 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/ParamMap.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/ParamMap.java
@@ -1,16 +1,29 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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 com.google.gson.webservice.definition;
 
 import java.lang.reflect.Type;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
 
-import com.google.common.base.Preconditions;
-import com.google.common.collect.Maps;
-
 class ParamMap {
 
   public static class Builder<T extends ParamMapSpec> {    
-    protected final Map<String, Object> contents = Maps.newLinkedHashMap();
+    protected final Map<String, Object> contents = new LinkedHashMap<String, Object>();
     protected final T spec;
 
     public Builder(T spec) {
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/Preconditions.java b/wsdef/src/main/java/com/google/gson/webservice/definition/Preconditions.java
new file mode 100644
index 00000000..5fd1a506
--- /dev/null
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/Preconditions.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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 com.google.gson.webservice.definition;
+
+final class Preconditions {
+
+  public static void checkArgument(boolean condition) {
+    if (!condition) {
+      throw new IllegalArgumentException();
+    }
+  }
+
+  public static void checkNotNull(Object obj) {
+    if (obj == null) {
+      throw new IllegalArgumentException();
+    }
+  }
+}
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBody.java b/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBody.java
index a0939dde..beaf1668 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBody.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBody.java
@@ -18,8 +18,6 @@ package com.google.gson.webservice.definition;
 import java.lang.reflect.Type;
 import java.util.Map;
 
-import com.google.inject.Inject;
-
 /**
  * Definition of the request body of a {@link WebServiceCall}. The request body is what is sent out
  * in the output stream of the request (for example, with 
@@ -32,7 +30,6 @@ public final class RequestBody extends ContentBody {
 
   public static class Builder extends ParamMap.Builder<RequestBodySpec> {    
     
-    @Inject
     public Builder(RequestBodySpec spec) {
       super(spec);
     }
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBodySpec.java b/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBodySpec.java
index 78f5232f..19c77f1d 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBodySpec.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/RequestBodySpec.java
@@ -16,10 +16,9 @@
 package com.google.gson.webservice.definition;
 
 import java.lang.reflect.Type;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
-import com.google.common.collect.Maps;
-
 /**
  * Specification of a {@link RequestBody}.
  * 
@@ -28,7 +27,7 @@ import com.google.common.collect.Maps;
 public final class RequestBodySpec extends ContentBodySpec {
   
   public static class Builder {
-    private final Map<String, Type> paramsSpec = Maps.newLinkedHashMap();
+    private final Map<String, Type> paramsSpec = new LinkedHashMap<String, Type>();
     public Builder add(String paramName, Type type) {
       paramsSpec.put(paramName, type);
       return this;
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/RequestSpec.java b/wsdef/src/main/java/com/google/gson/webservice/definition/RequestSpec.java
index 01cb4463..8c49b892 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/RequestSpec.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/RequestSpec.java
@@ -15,8 +15,6 @@
  */
 package com.google.gson.webservice.definition;
 
-import com.google.common.base.Preconditions;
-
 /**
  * Specification for a {@link WebServiceRequest}.
  * 
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBody.java b/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBody.java
index 29fe5c0a..bd9a0e2d 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBody.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBody.java
@@ -18,8 +18,6 @@ package com.google.gson.webservice.definition;
 import java.lang.reflect.Type;
 import java.util.Map;
 
-import com.google.inject.Inject;
-
 /**
  * body of the response. This is written out as JSON to be sent out to the client. 
  * 
@@ -29,7 +27,6 @@ public final class ResponseBody extends ContentBody {
 
   public static class Builder extends ParamMap.Builder<ResponseBodySpec> {    
 
-    @Inject
     public Builder(ResponseBodySpec spec) {
       super(spec);
     }
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBodySpec.java b/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBodySpec.java
index 6b801d69..a8863e5f 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBodySpec.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseBodySpec.java
@@ -16,10 +16,9 @@
 package com.google.gson.webservice.definition;
 
 import java.lang.reflect.Type;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
-import com.google.common.collect.Maps;
-
 /**
  * Specification of a {@link ResponseBody}.
  * 
@@ -28,7 +27,7 @@ import com.google.common.collect.Maps;
 public final class ResponseBodySpec extends ContentBodySpec {
   
   public static class Builder {
-    private final Map<String, Type> paramsSpec = Maps.newLinkedHashMap();
+    private final Map<String, Type> paramsSpec = new LinkedHashMap<String, Type>();
     public Builder add(String paramName, Type type) {
       paramsSpec.put(paramName, type);
       return this;
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseSpec.java b/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseSpec.java
index 3e0e21b7..b7373b9c 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseSpec.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/ResponseSpec.java
@@ -15,8 +15,6 @@
  */
 package com.google.gson.webservice.definition;
 
-import com.google.common.base.Preconditions;
-
 /**
  * Specification for a {@link WebServiceResponse}.
  * 
diff --git a/wsdef/src/main/java/com/google/gson/webservice/definition/WebServiceCallSpec.java b/wsdef/src/main/java/com/google/gson/webservice/definition/WebServiceCallSpec.java
index 76f2bc25..f7e29498 100644
--- a/wsdef/src/main/java/com/google/gson/webservice/definition/WebServiceCallSpec.java
+++ b/wsdef/src/main/java/com/google/gson/webservice/definition/WebServiceCallSpec.java
@@ -20,8 +20,6 @@ import java.util.Arrays;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
-import com.google.common.base.Preconditions;
-
 
 /**
  * Specification for a Json web service call. The call includes the relative path where the call