diff --git a/src/main/java/io/github/pgullah/jsr/conversion/MethodArgsConverter.java b/src/main/java/io/github/pgullah/jsr/conversion/MethodArgsConverter.java
index f6c5813..6065726 100644
--- a/src/main/java/io/github/pgullah/jsr/conversion/MethodArgsConverter.java
+++ b/src/main/java/io/github/pgullah/jsr/conversion/MethodArgsConverter.java
@@ -1,7 +1,5 @@
 package io.github.pgullah.jsr.conversion;
 
-import java.util.Collection;
-
 public interface MethodArgsConverter extends TypeConverter<String[], Object[]> {
 
     /**
diff --git a/src/main/java/io/github/pgullah/jsr/model/TestSpec.java b/src/main/java/io/github/pgullah/jsr/model/TestSpec.java
index f9e545e..4b85f22 100644
--- a/src/main/java/io/github/pgullah/jsr/model/TestSpec.java
+++ b/src/main/java/io/github/pgullah/jsr/model/TestSpec.java
@@ -10,6 +10,16 @@ public record TestSpec(String path, Class<?> sourceClass, String method,
                        Optional<Class<? extends MethodArgsConverter>> argsConverter,
                        Optional<Class<? extends TypeConverter<String, ?>>> resultConverter) {
 
+    public TestSpec {
+        if (argsConverter.filter(c -> c == MethodArgsConverter.None.class).isPresent()) {
+            throw new IllegalArgumentException("Method args converter must not be of None type");
+        }
+
+        if (resultConverter.filter(c -> c == TypeConverter.None.class).isPresent()) {
+            throw new IllegalArgumentException("Result converter must not be of None type");
+        }
+    }
+
     public static Builder testSpecBuilderOf(String path, Class<?> sourceClass, String method) {
         return new Builder(path, sourceClass, method);
     }
@@ -53,5 +63,4 @@ public TestSpec build() {
                     Optional.ofNullable(resultConverter));
         }
     }
-
 }
diff --git a/src/main/java/io/github/pgullah/jsr/provider/TestSpecProvider.java b/src/main/java/io/github/pgullah/jsr/provider/TestSpecProvider.java
index ad64c1c..a37abf3 100644
--- a/src/main/java/io/github/pgullah/jsr/provider/TestSpecProvider.java
+++ b/src/main/java/io/github/pgullah/jsr/provider/TestSpecProvider.java
@@ -27,7 +27,11 @@ public Builder addAnnotated(Class<?>... classes) {
         }
 
         public Builder addSimple(String specPath, Class<?> clazz, String method) {
-            providerList.add(() -> Stream.of(TestSpec.testSpecBuilderOf(specPath, clazz, method).build()));
+            return addSimple(TestSpec.testSpecBuilderOf(specPath, clazz, method).build());
+        }
+
+        public Builder addSimple(TestSpec testSpec) {
+            providerList.add(() -> Stream.of(testSpec));
             return this;
         }
 
diff --git a/src/test/java/io/github/pgullah/jsr/examples/TestSpecRunner.java b/src/test/java/io/github/pgullah/jsr/examples/TestSpecRunner.java
index 5cedfdc..ac12d7c 100644
--- a/src/test/java/io/github/pgullah/jsr/examples/TestSpecRunner.java
+++ b/src/test/java/io/github/pgullah/jsr/examples/TestSpecRunner.java
@@ -4,8 +4,11 @@
 import io.github.pgullah.jsr.examples.sut.FizzBuzz;
 import io.github.pgullah.jsr.examples.sut.RegexMatching;
 import io.github.pgullah.jsr.AbstractGenericTestRunner;
+import io.github.pgullah.jsr.model.TestSpec;
 import io.github.pgullah.jsr.provider.TestSpecProvider;
 
+import static io.github.pgullah.jsr.model.TestSpec.testSpecBuilderOf;
+
 public class TestSpecRunner extends AbstractGenericTestRunner {
 
     @Override
@@ -13,6 +16,10 @@ public TestSpecProvider testSpecProvider() {
         return TestSpecProvider.builder()
                 .addAnnotated(ClassMethodTaggedWithSpecAnnotation.class)
                 .addSimple("/specs/simple.spec", FizzBuzz.class, "solution")
+                .addSimple(testSpecBuilderOf("/specs/simple-with-header.spec", FizzBuzz.class, "solution")
+                        .includeHeader(true)
+                        .build()
+                )
                 .addSimple("/specs/multi-test-methods.spec", RegexMatching.class, "solution.*")
                 .build();
     }
diff --git a/src/test/java/io/github/pgullah/jsr/examples/sut/FizzBuzz.java b/src/test/java/io/github/pgullah/jsr/examples/sut/FizzBuzz.java
index 64eadde..2cec16c 100644
--- a/src/test/java/io/github/pgullah/jsr/examples/sut/FizzBuzz.java
+++ b/src/test/java/io/github/pgullah/jsr/examples/sut/FizzBuzz.java
@@ -15,7 +15,7 @@ public String[] solution(int number) {
                 }
                 fizzOrBuzz += "Buzz";
             }
-            objects[i-1] = fizzOrBuzz.isEmpty() ? ""+i : fizzOrBuzz;
+            objects[i-1] = fizzOrBuzz.isEmpty() ? String.valueOf(i) : fizzOrBuzz;
         }
         return objects;
     }
diff --git a/src/test/resources/specs/simple-with-header.spec b/src/test/resources/specs/simple-with-header.spec
new file mode 100644
index 0000000..c1038b1
--- /dev/null
+++ b/src/test/resources/specs/simple-with-header.spec
@@ -0,0 +1,4 @@
+inputNumber,expectedResult
+3, "[1,2,Fizz]"
+10,"[1,2,Fizz,4,Buzz,Fizz,7,8,Fizz,Buzz]"
+20,"[1,2,Fizz,4,Buzz,Fizz,7,8,Fizz,Buzz,11,Fizz,13,14,Fizz Buzz,16,17,Fizz,19,Buzz]"
\ No newline at end of file