diff --git a/jOOQ/src/main/java/org/jooq/Result.java b/jOOQ/src/main/java/org/jooq/Result.java
index ea8e4c2fa8..6b73defec6 100644
--- a/jOOQ/src/main/java/org/jooq/Result.java
+++ b/jOOQ/src/main/java/org/jooq/Result.java
@@ -1844,7 +1844,8 @@ public interface Result<R extends Record> extends FieldProvider, List<R>, Attach
      * are non-unique.
      *
      * @param keys The keys. Client code must assure that keys are unique in the
-     *            result set.
+     *            result set. If this is <code>null</code> or an empty array,
+     *            the resulting map will contain at most one entry.
      * @return A Map containing the results.
      * @throws InvalidResultException if the keys are non-unique in the result
      *             set.
@@ -1886,7 +1887,8 @@ public interface Result<R extends Record> extends FieldProvider, List<R>, Attach
      * Unlike {@link #intoMap(Field[])}, this method allows for non-unique keys
      * in the result set.
      *
-     * @param keys The keys.
+     * @param keys The keys. If this is <code>null</code> or an empty array, the
+     *            resulting map will contain at most one entry.
      * @return A Map containing grouped results
      */
     Map<List<?>, Result<R>> intoGroups(Field<?>[] keys);
diff --git a/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java b/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java
index 658e4c93e6..5f5e556bce 100644
--- a/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java
@@ -1393,8 +1393,8 @@ class ResultImpl<R extends Record> implements Result<R>, AttachableInternal {
 
     @Override
     public final Map<List<?>, R> intoMap(Field<?>[] keys) {
-        if (keys == null || keys.length == 0) {
-            throw new IllegalArgumentException("Keys must not be null or empty.");
+        if (keys == null) {
+            keys = new Field[0];
         }
 
         Map<List<?>, R> map = new LinkedHashMap<List<?>, R>();
@@ -1454,8 +1454,8 @@ class ResultImpl<R extends Record> implements Result<R>, AttachableInternal {
 
     @Override
     public final Map<List<?>, Result<R>> intoGroups(Field<?>[] keys) {
-        if (keys == null || keys.length == 0) {
-            throw new IllegalArgumentException("Keys must not be null or empty.");
+        if (keys == null) {
+            keys = new Field[0];
         }
 
         Map<List<?>, Result<R>> map = new LinkedHashMap<List<?>, Result<R>>();