diff --git a/README.md b/README.md
index 38df8651e..81a34328e 100644
--- a/README.md
+++ b/README.md
@@ -232,13 +232,13 @@ If [Avaje-Jsonb](https://github.com/avaje/avaje-jsonb) is detected, http generat
 public class WidgetController$Route implements WebRoutes {
 
   private final WidgetController controller;
-  private final JsonType<java.util.List<org.example.hello.WidgetController.Widget>> listWidgetJsonType;
-  private final JsonType<org.example.hello.WidgetController.Widget> widgetJsonType;
+  private final JsonType<List<Widget>> listWidgetJsonType;
+  private final JsonType<Widget> widgetJsonType;
 
   public WidgetController$Route(WidgetController controller, Jsonb jsonB) {
     this.controller = controller;
-    this.listWidgetJsonType = jsonB.type(org.example.hello.WidgetController.Widget.class).list();
-    this.widgetJsonType = jsonB.type(org.example.hello.WidgetController.Widget.class);
+    this.listWidgetJsonType = jsonB.type(Widget.class).list();
+    this.widgetJsonType = jsonB.type(Widget.class);
   }
 
   @Override
diff --git a/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientMethodWriter.java b/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientMethodWriter.java
index 5c0abe1d2..927ad5fe7 100644
--- a/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientMethodWriter.java
+++ b/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientMethodWriter.java
@@ -4,6 +4,7 @@
 
 import javax.lang.model.element.TypeElement;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * Write code to register Web route for a given controller method.
@@ -22,24 +23,21 @@ class ClientMethodWriter {
   private final UType returnType;
   private MethodParam bodyHandlerParam;
   private String methodGenericParams = "";
+  private final boolean useJsonb;
 
-  ClientMethodWriter(MethodReader method, Append writer, ProcessingContext ctx) {
+  ClientMethodWriter(MethodReader method, Append writer, ProcessingContext ctx, boolean useJsonb) {
     this.method = method;
     this.writer = writer;
     this.webMethod = method.webMethod();
     this.ctx = ctx;
     this.returnType = Util.parseType(method.returnType());
+    this.useJsonb = useJsonb;
   }
 
   void addImportTypes(ControllerReader reader) {
     reader.addImportTypes(returnType.importTypes());
     for (final MethodParam param : method.params()) {
-      final var type = param.utype();
-      final var type0 = type.param0();
-      final var type1 = type.param1();
-      reader.addImportType(type.mainType().replace("[]", ""));
-      if (type0 != null) reader.addImportType(type0.replace("[]", ""));
-      if (type1 != null) reader.addImportType(type1.replace("[]", ""));
+      reader.addImportTypes(param.utype().importTypes());
     }
   }
 
@@ -116,37 +114,54 @@ private void writeEnd() {
 
   private void writeSyncResponse() {
     writer.append("      ");
-    String type0 = returnType.mainType();
-    String type1 = returnType.param0();
-    writeResponse(type0, type1);
+    writeResponse(returnType);
   }
 
   private void writeAsyncResponse() {
     writer.append("      .async()");
-    String type0 = returnType.param0();
-    String type1 = returnType.param1();
-    writeResponse(type0, type1);
+    writeResponse(returnType.paramRaw());
   }
 
   private void writeCallResponse() {
     writer.append("      .call()");
-    String type0 = returnType.param0();
-    String type1 = returnType.param1();
-    writeResponse(type0, type1);
+    writeResponse(returnType.paramRaw());
   }
 
-  private void writeResponse(String type0, String type1) {
-    if (isList(type0)) {
-      writer.append(".list(%s.class);", Util.shortName(type1)).eol();
-    } else if (isStream(type0)) {
-      writer.append(".stream(%s.class);", Util.shortName(type1)).eol();
-    } else if (isHttpResponse(type0)){
+  private void writeResponse(UType type) {
+    final var mainType = type.mainType();
+    final var param1 = type.paramRaw();
+    if (isList(mainType)) {
+      writer.append(".list(");
+      writeGeneric(param1);
+    } else if (isStream(mainType)) {
+      writer.append(".stream(");
+      writeGeneric(param1);
+    } else if (isHttpResponse(mainType)) {
       writeWithHandler();
     } else {
-      writer.append(".bean(%s.class);", Util.shortName(type0)).eol();
+      writer.append(".bean(");
+      writeGeneric(type);
     }
   }
 
+  void writeGeneric(UType type) {
+    if (useJsonb && type.isGeneric()) {
+      final var params =
+          type.importTypes().stream()
+                  .skip(1)
+                  .map(Util::shortName)
+                  .collect(Collectors.joining(".class, "));
+
+      writer.append(
+          "Types.newParameterizedType(%s.class, %s.class)", Util.shortName(type.mainType()), params);
+    } else {
+      writer.append("%s.class", Util.shortName(type.mainType()));
+    }
+    writer.append(");");
+
+    writer.eol();
+  }
+
   private void writeWithHandler() {
     if (bodyHandlerParam != null) {
       writer.append(".handler(%s);", bodyHandlerParam.name()).eol();
diff --git a/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientProcessor.java b/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientProcessor.java
index 0a8b68605..c3f4010bf 100644
--- a/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientProcessor.java
+++ b/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientProcessor.java
@@ -27,6 +27,22 @@ public class ClientProcessor extends AbstractProcessor {
 
   protected ProcessingContext ctx;
 
+  private final boolean useJsonB;
+
+  public ClientProcessor() {
+    var jsonBOnClassPath = false;
+    try {
+      Class.forName("io.avaje.jsonb.Jsonb");
+      jsonBOnClassPath = true;
+    } catch (final ClassNotFoundException e) {
+    }
+    useJsonB = jsonBOnClassPath;
+  }
+
+  public ClientProcessor(boolean useJsonb) {
+    useJsonB = useJsonb;
+  }
+
   @Override
   public SourceVersion getSupportedSourceVersion() {
     return SourceVersion.latest();
@@ -107,7 +123,7 @@ private void writeClient(Element controller) {
   }
 
   protected String writeClientAdapter(ProcessingContext ctx, ControllerReader reader) throws IOException {
-    return new ClientWriter(reader, ctx).write();
+    return new ClientWriter(reader, ctx, useJsonB).write();
   }
 
 }
diff --git a/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientWriter.java b/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientWriter.java
index 26dd12a6a..6f465bd73 100644
--- a/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientWriter.java
+++ b/http-generator-client/src/main/java/io/avaje/http/generator/client/ClientWriter.java
@@ -21,12 +21,15 @@ class ClientWriter extends BaseControllerWriter {
   private static final String SUFFIX = "HttpClient";
 
   private final List<ClientMethodWriter> methodList = new ArrayList<>();
+  private final boolean useJsonb;
 
-  ClientWriter(ControllerReader reader, ProcessingContext ctx) throws IOException {
+  ClientWriter(ControllerReader reader, ProcessingContext ctx, boolean useJsonB) throws IOException {
     super(reader, ctx, SUFFIX);
     reader.addImportType(HTTP_CLIENT_CONTEXT);
     reader.addImportType(HTTP_API_PROVIDER);
+    this.useJsonb = useJsonB;
     readMethods();
+    if (useJsonB) reader.addImportType("io.avaje.jsonb.Types");
   }
 
   @Override
@@ -38,7 +41,7 @@ protected String initPackageName(String originName) {
   private void readMethods() {
     for (MethodReader method : reader.methods()) {
       if (method.isWebMethod()) {
-        ClientMethodWriter methodWriter = new ClientMethodWriter(method, writer, ctx);
+        final var methodWriter = new ClientMethodWriter(method, writer, ctx, useJsonb);
         methodWriter.addImportTypes(reader);
         methodList.add(methodWriter);
       }
diff --git a/http-generator-core/src/main/java/io/avaje/http/generator/core/JsonBUtil.java b/http-generator-core/src/main/java/io/avaje/http/generator/core/JsonBUtil.java
index 78365b3f2..f338f69d0 100644
--- a/http-generator-core/src/main/java/io/avaje/http/generator/core/JsonBUtil.java
+++ b/http-generator-core/src/main/java/io/avaje/http/generator/core/JsonBUtil.java
@@ -3,6 +3,7 @@
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
 
 public class JsonBUtil {
   private JsonBUtil() {}
@@ -40,23 +41,46 @@ public static void writeJsonbType(UType type, Append writer) {
 
     writer.append("    this.%sJsonType = jsonB.type(", type.shortName());
     if (!type.isGeneric()) {
-      writer.append("%s.class)", PrimitiveUtil.wrap(type.full()));
+      writer.append("%s.class)", Util.shortName(PrimitiveUtil.wrap(type.full())));
     } else {
       switch (type.mainType()) {
         case "java.util.List":
-          writer.append("%s.class).list()", type.param0());
+          writeType(type.paramRaw(), writer);
+          writer.append(".list()");
           break;
         case "java.util.Set":
-          writer.append("%s.class).set()", type.param0());
+          writeType(type.paramRaw(), writer);
+          writer.append(".set()");
           break;
         case "java.util.Map":
-          writer.append("%s.class).map()", type.param1());
+          writeType(type.paramRaw(), writer);
+          writer.append(".map()");
           break;
         default:
-          throw new UnsupportedOperationException(
-              "Only java.util Map, Set and List are supported JsonB Controller Collection Types");
+          {
+            if (type.mainType().contains("java.util"))
+              throw new UnsupportedOperationException(
+                  "Only java.util Map, Set and List are supported JsonB Controller Collection Types");
+            writeType(type, writer);
+          }
       }
     }
     writer.append(";").eol();
   }
+
+  static void writeType(UType type, Append writer) {
+    if (type.isGeneric()) {
+      final var params =
+          type.importTypes().stream()
+              .skip(1)
+              .map(Util::shortName)
+              .collect(Collectors.joining(".class, "));
+
+      writer.append(
+          "Types.newParameterizedType(%s.class, %s.class))",
+          Util.shortName(type.mainType()), params);
+    } else {
+      writer.append("%s.class)", Util.shortName(type.mainType()));
+    }
+  }
 }
diff --git a/http-generator-core/src/main/java/io/avaje/http/generator/core/UType.java b/http-generator-core/src/main/java/io/avaje/http/generator/core/UType.java
index dd2f2d4d6..e4a4bd20b 100644
--- a/http-generator-core/src/main/java/io/avaje/http/generator/core/UType.java
+++ b/http-generator-core/src/main/java/io/avaje/http/generator/core/UType.java
@@ -11,6 +11,10 @@ public interface UType {
   static UType parse(TypeMirror type) {
     return Util.parseType(type);
   }
+  /** Create the UType from the given String. */
+  static UType parse(String type) {
+    return Util.parse(type);
+  }
 
   UType VOID = new VoidType();
 
@@ -48,9 +52,12 @@ default String param1() {
     return null;
   }
 
-  /**
-   * Return the raw type.
-   */
+  /** Return the raw generic parameter if this UType is a Collection. */
+  default UType paramRaw() {
+    return null;
+  }
+
+  /** Return the raw type. */
   String full();
 
   default boolean isGeneric() {
@@ -106,7 +113,9 @@ public String full() {
 
     @Override
     public Set<String> importTypes() {
-      return Collections.singleton(rawType);
+      return rawType.startsWith("java.lang.") && rawType.indexOf('.') > -1
+          ? Set.of()
+          : Collections.singleton(rawType.replace("[]", ""));
     }
 
     @Override
@@ -130,15 +139,38 @@ public String mainType() {
    */
   class Generic implements UType {
     final String rawType;
+    final UType rawParamType;
     final List<String> allTypes;
     final String shortRawType;
     final String shortName;
 
     Generic(String rawTypeInput) {
-      this.rawType = rawTypeInput.replace(" ",""); // trim whitespace
+      this.rawType = rawTypeInput.replace(" ", ""); // trim whitespace
       this.allTypes = Arrays.asList(rawType.split("[<|>|,]"));
       this.shortRawType = shortRawType(rawType, allTypes);
       this.shortName = Util.name(shortRawType);
+      final var paramTypeString = extractRawParam();
+      this.rawParamType = paramTypeString != null ? UType.parse(paramTypeString) : null;
+    }
+
+    private String extractRawParam() {
+
+      switch (mainType()) {
+        case "java.util.Set":
+        case "java.util.List":
+        case "java.util.stream.Stream":
+        case "java.util.concurrent.CompletableFuture":
+        case "io.avaje.http.client.HttpCall":
+          var first = rawType.indexOf("<") + 1;
+          var end = rawType.lastIndexOf(">");
+          return rawType.substring(first, end);
+        case "java.util.Map":
+          first = rawType.indexOf(",") + 1;
+          end = rawType.lastIndexOf(">");
+          return rawType.substring(first, end);
+        default:
+          return null;
+      }
     }
 
     private String shortRawType(String rawType, List<String> allTypes) {
@@ -163,7 +195,7 @@ public Set<String> importTypes() {
       Set<String> set = new LinkedHashSet<>();
       for (String type : allTypes) {
         if (!type.startsWith("java.lang.") && type.indexOf('.') > -1) {
-          set.add(type);
+          set.add(type.replace("[]", ""));
         }
       }
       return set;
@@ -210,5 +242,10 @@ public String param0() {
     public String param1() {
       return allTypes.size() < 3 ? null : allTypes.get(2);
     }
+
+    @Override
+    public UType paramRaw() {
+      return rawParamType;
+    }
   }
 }
diff --git a/http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/ControllerMethodWriter.java b/http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/ControllerMethodWriter.java
index e2df2842e..a43192644 100644
--- a/http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/ControllerMethodWriter.java
+++ b/http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/ControllerMethodWriter.java
@@ -103,7 +103,7 @@ private void writeContextReturn() {
     } else if (MediaType.TEXT_PLAIN.equalsIgnoreCase(produces)) {
       writer.append("    res.writerContext().contentType(io.helidon.common.http.MediaType.TEXT_PLAIN);").eol();
     } else {
-      writer.append(    "res.writerContext().contentType(io.helidon.common.http.MediaType.parse(\"%s\"));", produces).eol();
+      writer.append("    res.writerContext().contentType(io.helidon.common.http.MediaType.parse(\"%s\"));", produces).eol();
     }
   }
 
diff --git a/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/ControllerWriter.java b/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/ControllerWriter.java
index 7f19e1ccc..957c293fb 100644
--- a/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/ControllerWriter.java
+++ b/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/ControllerWriter.java
@@ -1,10 +1,17 @@
 package io.avaje.http.generator.javalin;
 
-import io.avaje.http.generator.core.*;
-
 import java.io.IOException;
 import java.util.Map;
 
+import io.avaje.http.generator.core.BaseControllerWriter;
+import io.avaje.http.generator.core.Constants;
+import io.avaje.http.generator.core.ControllerReader;
+import io.avaje.http.generator.core.JsonBUtil;
+import io.avaje.http.generator.core.MethodReader;
+import io.avaje.http.generator.core.PrimitiveUtil;
+import io.avaje.http.generator.core.ProcessingContext;
+import io.avaje.http.generator.core.UType;
+
 /**
  * Write Javalin specific Controller WebRoute handling adapter.
  */
@@ -21,7 +28,11 @@ class ControllerWriter extends BaseControllerWriter {
     if (useJsonB) {
       reader.addImportType("io.avaje.jsonb.Jsonb");
       reader.addImportType("io.avaje.jsonb.JsonType");
+      reader.addImportType("io.avaje.jsonb.Types");
       this.jsonTypes = JsonBUtil.jsonTypes(reader);
+      jsonTypes.values().stream()
+          .map(UType::importTypes)
+          .forEach(reader::addImportTypes);
     } else {
       this.jsonTypes = Map.of();
     }
@@ -77,7 +88,9 @@ private void writeClassStart() {
     }
 
     for (final UType type : jsonTypes.values()) {
-      writer.append("  private final JsonType<%s> %sJsonType;", PrimitiveUtil.wrap(type.full()), type.shortName()).eol();
+      final var typeString = PrimitiveUtil.wrap(type.shortType()).replace(",", ", ");
+
+      writer.append("  private final JsonType<%s> %sJsonType;", typeString, type.shortName()).eol();
     }
     writer.eol();
 
diff --git a/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/JavalinProcessor.java b/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/JavalinProcessor.java
index 4d6285675..ef65ccdf9 100644
--- a/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/JavalinProcessor.java
+++ b/http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/JavalinProcessor.java
@@ -9,15 +9,16 @@
 
 public class JavalinProcessor extends BaseProcessor {
 
-  private boolean useJsonB;
+  private final boolean useJsonB;
 
   public JavalinProcessor() {
+    var jsonBOnClassPath = false;
     try {
       Class.forName("io.avaje.jsonb.Jsonb");
-      this.useJsonB = true;
+      jsonBOnClassPath = true;
     } catch (final ClassNotFoundException e) {
-      this.useJsonB = false;
     }
+    useJsonB = jsonBOnClassPath;
   }
 
   public JavalinProcessor(boolean useJsonb) {
diff --git a/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/ControllerWriter.java b/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/ControllerWriter.java
index 1d78d70ab..03118e01e 100644
--- a/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/ControllerWriter.java
+++ b/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/ControllerWriter.java
@@ -5,6 +5,7 @@
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * Write Helidon specific web route adapter (a Helidon Service).
@@ -21,7 +22,11 @@ class ControllerWriter extends BaseControllerWriter {
     if (useJsonB) {
       reader.addImportType("io.avaje.jsonb.Jsonb");
       reader.addImportType("io.avaje.jsonb.JsonType");
+      reader.addImportType("io.avaje.jsonb.Types");
       this.jsonTypes = JsonBUtil.jsonTypes(reader);
+      jsonTypes.values().stream()
+          .map(UType::importTypes)
+          .forEach(reader::addImportTypes);
     } else {
       this.jsonTypes = Map.of();
     }
@@ -87,7 +92,9 @@ private void writeClassStart() {
       writer.append("  private final Validator validator;").eol();
     }
     for (final UType type : jsonTypes.values()) {
-      writer.append("  private final JsonType<%s> %sJsonType;", PrimitiveUtil.wrap(type.full()), type.shortName()).eol();
+      final var typeString = PrimitiveUtil.wrap(type.shortType()).replace(",", ", ");
+
+      writer.append("  private final JsonType<%s> %sJsonType;", typeString, type.shortName()).eol();
     }
     writer.eol();
 
diff --git a/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/NimaProcessor.java b/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/NimaProcessor.java
index c65a83b6a..cf3464093 100644
--- a/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/NimaProcessor.java
+++ b/http-generator-nima/src/main/java/io/avaje/http/generator/helidon/nima/NimaProcessor.java
@@ -9,15 +9,16 @@
 
 public class NimaProcessor extends BaseProcessor {
 
-  private boolean jsonB;
+  private final boolean jsonB;
 
   public NimaProcessor() {
+    var jsonBOnClassPath = false;
     try {
       Class.forName("io.avaje.jsonb.Jsonb");
-      this.jsonB = true;
+      jsonBOnClassPath = true;
     } catch (final ClassNotFoundException e) {
-      this.jsonB = false;
     }
+    jsonB = jsonBOnClassPath;
   }
 
   public NimaProcessor(boolean useJsonb) {
diff --git a/tests/test-client/pom.xml b/tests/test-client/pom.xml
index 8dc3b7938..9babe4139 100644
--- a/tests/test-client/pom.xml
+++ b/tests/test-client/pom.xml
@@ -30,7 +30,7 @@
     <dependency>
       <groupId>io.avaje</groupId>
       <artifactId>avaje-http-client</artifactId>
-      <version>1.16</version>
+      <version>1.20</version>
     </dependency>
 
     <dependency>