diff --git a/src/pvaClient.cpp b/src/pvaClient.cpp
index 6697d59..c5f1d81 100644
--- a/src/pvaClient.cpp
+++ b/src/pvaClient.cpp
@@ -27,7 +27,7 @@ using namespace std;
 namespace epics { namespace pvaClient { 
 
 
-class PvaClientChannelCache
+class epicsShareClass PvaClientChannelCache
 {
 public:
     PvaClientChannelCache(){}
diff --git a/src/pvaClientChannel.cpp b/src/pvaClientChannel.cpp
index 4ef0d7d..9d8e9a9 100644
--- a/src/pvaClientChannel.cpp
+++ b/src/pvaClientChannel.cpp
@@ -26,7 +26,7 @@ using namespace std;
 namespace epics { namespace pvaClient {
 
 
-class PvaClientGetCache
+class epicsShareClass PvaClientGetCache
 {
 public:
     PvaClientGetCache(){}
@@ -73,7 +73,7 @@ size_t PvaClientGetCache::cacheSize()
 
 }
 
-class PvaClientPutCache
+class epicsShareClass PvaClientPutCache
 {
 public:
     PvaClientPutCache(){}