diff --git a/src/pv/pvData.h b/src/pv/pvData.h
index 7798aec..e045cb1 100644
--- a/src/pv/pvData.h
+++ b/src/pv/pvData.h
@@ -1570,7 +1570,7 @@ epicsShareExtern PVDataCreatePtr getPVDataCreate();
  * stream support for pvField
  */
 namespace std{
-    std::ostream& operator<<(std::ostream& o, const epics::pvData::PVField *ptr);
+    epicsShareExtern std::ostream& operator<<(std::ostream& o, const epics::pvData::PVField *ptr);
 }
 
 #endif  /* PVDATA_H */
diff --git a/src/pv/pvIntrospect.h b/src/pv/pvIntrospect.h
index 53d236f..cde0421 100644
--- a/src/pv/pvIntrospect.h
+++ b/src/pv/pvIntrospect.h
@@ -1225,7 +1225,7 @@ struct StructureArrayHashFunction {
  * stream support for Field
  */
 namespace std{
-    std::ostream& operator<<(std::ostream& o, const epics::pvData::Field *ptr);
+    epicsShareExtern std::ostream& operator<<(std::ostream& o, const epics::pvData::Field *ptr);
 }
 
 #endif  /* PVINTROSPECT_H */