diff --git a/src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp b/src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp
index c51f4f164895d..026f352701d29 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp
@@ -141,10 +141,12 @@
           "GC heuristics to use. This fine-tunes the GC mode selected, "    \
           "by choosing when to start the GC, how much to process on each "  \
           "cycle, and what other features to automatically enable. "        \
-          "Possible values are:"                                            \
+          "When -XX:ShenandoahGCMode is generational, the only supported "  \
+          "option is the default, adaptive. Possible values are:"           \
           " adaptive - adapt to maintain the given amount of free heap "    \
           "at all times, even during the GC cycle;"                         \
-          " static -  trigger GC when free heap falls below the threshold;" \
+          " static - trigger GC when free heap falls below a specified "    \
+          "threshold;"                                                      \
           " aggressive - run GC continuously, try to evacuate everything;"  \
           " compact - run GC more frequently and with deeper targets to "   \
           "free up more memory.")                                           \
diff --git a/src/java.base/share/man/java.md b/src/java.base/share/man/java.md
index f7a31fff83612..18e208f292c6b 100644
--- a/src/java.base/share/man/java.md
+++ b/src/java.base/share/man/java.md
@@ -2883,6 +2883,46 @@ Java HotSpot VM.
     expensive operations. Using a lower value will cause heap memory to be
     uncommitted earlier, at the risk of soon having to commit it again.
 
+`-XX:+UseShenandoahGC`
+:   Enables the use of the Shenandoah garbage collector. This is a low pause
+    time, concurrent garbage collector. Its pause times are not proportional to
+    the size of the heap. Shenandoah garbage collector can work with compressed
+    pointers. See `-XX:UseCompressedOops` for further information about
+    compressed pointers.
+
+`-XX:ShenandoahGCMode=`*mode*
+:   Sets the GC mode for Shenandoah GC to use. By default, this option is set
+    to `satb`. Among other things, this defines which barriers are in use.
+    Possible mode values include the following:
+
+    `satb`
+    :   Snapshot-at-the-beginning concurrent GC (three pass mark-evac-update).
+        It is a single generation GC.
+
+    `generational`
+    :   It is also a snapshot-at-the-beginning and concurrent GC, but it is
+        generational. Please see [JEP 404](https://openjdk.org/jeps/404) and
+        [JEP 521](https://openjdk.org/jeps/521) for its advantages and risks.
+
+`-XX:ShenandoahGCHeuristics=`*heuristics*
+:   Sets the heuristics for Shenandoah GC to use. By default, this option is
+    set to `adaptive`. This fine-tunes the GC mode selected, by choosing when
+    to start the GC, how much to process on each cycle, and what other features
+    to automatically enable. When `-XX:ShenandoahGCMode` is `generational`, the
+    only supported option is the default, `adaptive`.
+
+    Possible heuristics are the following:
+
+    `adaptive`
+    :   To maintain the given amount of free heap at all times, even during
+        the GC cycle.
+
+    `static`
+    :   Trigger GC when free heap falls below a specified threshold.
+
+    `compact`
+    :   Run GC more frequently and with deeper targets to free up more memory.
+
 ## Deprecated Java Options
 
 These `java` options are deprecated and might be removed in a future JDK