diff --git a/src/hotspot/share/cds/archiveHeapWriter.cpp b/src/hotspot/share/cds/archiveHeapWriter.cpp
index b014caae3c716..8a4d104367227 100644
--- a/src/hotspot/share/cds/archiveHeapWriter.cpp
+++ b/src/hotspot/share/cds/archiveHeapWriter.cpp
@@ -87,7 +87,7 @@ void ArchiveHeapWriter::init() {
     _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000);
 
     guarantee(UseG1GC, "implementation limitation");
-    guarantee(MIN_GC_REGION_ALIGNMENT <= /*G1*/G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
+    guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
   }
 }
 
diff --git a/src/hotspot/share/gc/g1/g1ConcurrentMark.hpp b/src/hotspot/share/gc/g1/g1ConcurrentMark.hpp
index a76b7a03d06e0..f2206664b257a 100644
--- a/src/hotspot/share/gc/g1/g1ConcurrentMark.hpp
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMark.hpp
@@ -758,7 +758,7 @@ class G1CMTask : public TerminatorTerminator {
   G1CMOopClosure*             _cm_oop_closure;
 
   // Region this task is scanning, null if we're not scanning any
-  G1HeapRegion*                 _curr_region;
+  G1HeapRegion*               _curr_region;
   // Local finger of this task, null if we're not scanning a region
   HeapWord*                   _finger;
   // Limit of the region this task is scanning, null if we're not scanning one
diff --git a/src/hotspot/share/gc/g1/g1ConcurrentMarkBitMap.hpp b/src/hotspot/share/gc/g1/g1ConcurrentMarkBitMap.hpp
index 5c80e0d58fc70..6a141a7919b63 100644
--- a/src/hotspot/share/gc/g1/g1ConcurrentMarkBitMap.hpp
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMarkBitMap.hpp
@@ -36,7 +36,6 @@
 class G1CMBitMap;
 class G1CMTask;
 class G1ConcurrentMark;
-class G1HeapRegion;
 
 // Closure for iteration over bitmaps
 class G1CMBitMapClosure {
diff --git a/src/hotspot/share/gc/g1/g1FullGCCompactionPoint.hpp b/src/hotspot/share/gc/g1/g1FullGCCompactionPoint.hpp
index 8a5257ea09c4b..43131f9092ded 100644
--- a/src/hotspot/share/gc/g1/g1FullGCCompactionPoint.hpp
+++ b/src/hotspot/share/gc/g1/g1FullGCCompactionPoint.hpp
@@ -37,7 +37,7 @@ class PreservedMarks;
 class G1FullGCCompactionPoint : public CHeapObj<mtGC> {
   G1FullCollector* _collector;
   G1HeapRegion* _current_region;
-  HeapWord*   _compaction_top;
+  HeapWord* _compaction_top;
   PreservedMarks* _preserved_stack;
   GrowableArray<G1HeapRegion*>* _compaction_regions;
   GrowableArrayIterator<G1HeapRegion*> _compaction_region_iterator;
diff --git a/src/hotspot/share/gc/g1/g1OopClosures.hpp b/src/hotspot/share/gc/g1/g1OopClosures.hpp
index 84750967cbd40..965df8ea82a30 100644
--- a/src/hotspot/share/gc/g1/g1OopClosures.hpp
+++ b/src/hotspot/share/gc/g1/g1OopClosures.hpp
@@ -30,7 +30,6 @@
 #include "memory/iterator.hpp"
 #include "oops/markWord.hpp"
 
-class G1HeapRegion;
 class G1CollectedHeap;
 class G1RemSet;
 class G1ConcurrentMark;