1 files changed, 6 insertions, 3 deletions
diff --git a/src/main/java/com/squareup/javapoet/AnnotationSpec.java b/src/main/java/com/squareup/javapoet/AnnotationSpec.java
index d1c5e53..5525d7b 100644
--- a/src/main/java/com/squareup/javapoet/AnnotationSpec.java
+++ b/src/main/java/com/squareup/javapoet/AnnotationSpec.java
@@ -192,7 +192,8 @@ public final class AnnotationSpec {
 
   public static final class Builder {
     private final TypeName type;
-    private final Map<String, List<CodeBlock>> members = new LinkedHashMap<>();
+
+    public final Map<String, List<CodeBlock>> members = new LinkedHashMap<>();
 
     private Builder(TypeName type) {
       this.type = type;
@@ -203,8 +204,6 @@ public final class AnnotationSpec {
     }
 
     public Builder addMember(String name, CodeBlock codeBlock) {
-      checkNotNull(name, "name == null");
-      checkArgument(SourceVersion.isName(name), "not a valid name: %s", name);
       List<CodeBlock> values = members.computeIfAbsent(name, k -> new ArrayList<>());
       values.add(codeBlock);
       return this;
@@ -238,6 +237,10 @@ public final class AnnotationSpec {
     }
 
     public AnnotationSpec build() {
+      for (String name : members.keySet()) {
+        checkNotNull(name, "name == null");
+        checkArgument(SourceVersion.isName(name), "not a valid name: %s", name);
+      }
       return new AnnotationSpec(this);
     }
   }