diff --git a/src/hotspot/share/classfile/javaClasses.hpp b/src/hotspot/share/classfile/javaClasses.hpp
index 44d74a20aa96b..e6cfaed0c8749 100644
--- a/src/hotspot/share/classfile/javaClasses.hpp
+++ b/src/hotspot/share/classfile/javaClasses.hpp
@@ -25,6 +25,7 @@
 #ifndef SHARE_CLASSFILE_JAVACLASSES_HPP
 #define SHARE_CLASSFILE_JAVACLASSES_HPP
 
+#include "classfile/stringTable.hpp"
 #include "classfile/vmClasses.hpp"
 #include "oops/instanceKlass.hpp"
 #include "oops/oopsHierarchy.hpp"
@@ -197,7 +198,7 @@ class java_lang_String : AllStatic {
   // Debugging
   static void print(oop java_string, outputStream* st);
   friend class JavaClasses;
-  friend class StringTable;
+  friend class hotspot_jvm::StringTable;
 };
 
 
diff --git a/src/hotspot/share/classfile/stringTable.cpp b/src/hotspot/share/classfile/stringTable.cpp
index 89381b1a785f1..8c37324fb64b3 100644
--- a/src/hotspot/share/classfile/stringTable.cpp
+++ b/src/hotspot/share/classfile/stringTable.cpp
@@ -63,6 +63,8 @@
 #include "gc/g1/g1CollectedHeap.hpp"
 #endif
 
+namespace hotspot_jvm {
+
 // We prefer short chains of avg 2
 const double PREF_AVG_LIST_LEN = 2.0;
 // 2^24 is max size
@@ -764,6 +766,8 @@ void StringTable::dump(outputStream* st, bool verbose) {
   }
 }
 
+} // namespace hotspot_jvm
+
 // Utility for dumping strings
 StringtableDCmd::StringtableDCmd(outputStream* output, bool heap) :
                                  DCmdWithParser(output, heap),
@@ -778,6 +782,8 @@ void StringtableDCmd::execute(DCmdSource source, TRAPS) {
   VMThread::execute(&dumper);
 }
 
+namespace hotspot_jvm {
+
 // Sharing
 #if INCLUDE_CDS_JAVA_HEAP
 size_t StringTable::shared_entry_count() {
@@ -935,3 +941,5 @@ void StringTable::serialize_shared_table_header(SerializeClosure* soc) {
   soc->do_int(&_shared_strings_array_root_index);
 }
 #endif //INCLUDE_CDS_JAVA_HEAP
+
+} // namespace hotspot_jvm
diff --git a/src/hotspot/share/classfile/stringTable.hpp b/src/hotspot/share/classfile/stringTable.hpp
index 1b41c12ffedb4..2ce02cdb07635 100644
--- a/src/hotspot/share/classfile/stringTable.hpp
+++ b/src/hotspot/share/classfile/stringTable.hpp
@@ -37,6 +37,8 @@ class DumpedInternedStrings;
 class JavaThread;
 class SerializeClosure;
 
+namespace hotspot_jvm {
+
 class StringTable;
 class StringTableConfig;
 class StringTableCreateEntry;
@@ -158,4 +160,6 @@ class StringTable : public CHeapObj<mtSymbol>{
   static void verify();
 };
 
+} // namespace hotspot_jvm
+
 #endif // SHARE_CLASSFILE_STRINGTABLE_HPP
diff --git a/src/hotspot/share/precompiled/precompiled.hpp b/src/hotspot/share/precompiled/precompiled.hpp
index c6b8668010ed3..e8ecfaa851b1f 100644
--- a/src/hotspot/share/precompiled/precompiled.hpp
+++ b/src/hotspot/share/precompiled/precompiled.hpp
@@ -25,6 +25,12 @@
 // Precompiled headers are turned off if the user passes
 // --disable-precompiled-headers to configure.
 
+// The hotspot_jvm namespace using directive must be placed outside
+// #ifndef DONT_USE_PRECOMPILED_HEADER. That ensures it works with and
+// without precompiled headers.
+namespace hotspot_jvm {}
+using namespace hotspot_jvm;
+
 #ifndef DONT_USE_PRECOMPILED_HEADER
 
 // These header files are included in at least 130 C++ files, as of