diff --git a/common/fileview2/fvresultset.cpp b/common/fileview2/fvresultset.cpp
index 2c46aa66523..5974f407593 100644
--- a/common/fileview2/fvresultset.cpp
+++ b/common/fileview2/fvresultset.cpp
@@ -2342,11 +2342,12 @@ extern FILEVIEW_API unsigned writeResultCursorXml(IXmlWriterExt & writer, IResul
         writer.outputCString(schemaName, "@xmlSchema");
     if (xmlns)
     {
-        Owned<IPropertyIterator> it = const_cast<IProperties*>(xmlns)->getIterator();
+        Owned<IPropertyIterator> it = xmlns->getIterator();
         ForEach(*it)
         {
             const char *name = it->getPropKey();
-            writer.outputXmlns(name,const_cast<IProperties*>(xmlns)->queryProp(name));
+            const char *value = it->queryPropValue();
+            writer.outputXmlns(name,value);
         }
     }
     cursor->beginWriteXmlRows(writer);
diff --git a/common/pkgfiles/package.cpp b/common/pkgfiles/package.cpp
index 65a3998f902..0516a2473d5 100644
--- a/common/pkgfiles/package.cpp
+++ b/common/pkgfiles/package.cpp
@@ -52,7 +52,7 @@ void CPackageNode::mergeEnvironment(const CPackageNode *base)
     ForEach(*envIterator)
     {
         const char *id = envIterator->getPropKey();
-        const char *val = base->mergedEnvironment->queryProp(id);
+        const char *val = envIterator->queryPropValue();
         if (id && val && !mergedEnvironment->hasProp(id))
             mergedEnvironment->setProp(id, val);
     }
diff --git a/common/thorhelper/roxiedebug.cpp b/common/thorhelper/roxiedebug.cpp
index 7f0333072a4..7d1a9d220f7 100644
--- a/common/thorhelper/roxiedebug.cpp
+++ b/common/thorhelper/roxiedebug.cpp
@@ -898,7 +898,7 @@ void DebugActivityRecord::outputProperties(IXmlWriter *output)
         while (iterator->isValid())
         {
             const char *propName = iterator->getPropKey();
-            const char *propValue = properties->queryProp(propName);
+            const char *propValue = iterator->queryPropValue();
             output->outputBeginNested("att", false); output->outputCString(propName, "@name"); output->outputCString(propValue, "@value"); output->outputEndNested("att");
             iterator->next();
         }
@@ -1900,7 +1900,7 @@ void CBaseServerDebugContext::getCurrentGraphXGMML(IXmlWriter *output, bool orig
             while (iterator->isValid())
             {
                 const char *graphName = iterator->getPropKey();
-                const char *graphXML = completedGraphs->queryProp(graphName);
+                const char *graphXML = iterator->queryPropValue();
                 output->outputString(0, 0, NULL);
                 output->outputQuoted(graphXML);
                 iterator->next();
diff --git a/common/thorhelper/roxiehelper.cpp b/common/thorhelper/roxiehelper.cpp
index c4ced835b4a..20602b64535 100644
--- a/common/thorhelper/roxiehelper.cpp
+++ b/common/thorhelper/roxiehelper.cpp
@@ -2253,15 +2253,16 @@ void FlushingStringBuffer::startDataset(const char *elementName, const char *res
                             s.append("result_").append(sequence+1).append('\'');
                         if (xmlns)
                         {
-                            Owned<IPropertyIterator> it = const_cast<IProperties*>(xmlns)->getIterator(); //should fix IProperties to be const friendly
+                            Owned<IPropertyIterator> it = xmlns->getIterator();
                             ForEach(*it)
                             {
                                 const char *name = it->getPropKey();
+                                const char *value = it->queryPropValue();
                                 s.append(' ');
                                 if (!streq(name, "xmlns"))
                                     s.append("xmlns:");
                                 s.append(name).append("='");
-                                encodeUtf8XML(const_cast<IProperties*>(xmlns)->queryProp(name), s);
+                                encodeUtf8XML(value, s);
                                 s.append("'");
                             }
                         }
diff --git a/common/thorhelper/thorsoapcall.cpp b/common/thorhelper/thorsoapcall.cpp
index 67a1dcdd5f0..be9abd2b4b2 100644
--- a/common/thorhelper/thorsoapcall.cpp
+++ b/common/thorhelper/thorsoapcall.cpp
@@ -1920,7 +1920,7 @@ class CWSCAsyncFor : implements IWSCAsyncFor, public CInterface, public CAsyncFo
                 const char * key = iter->getPropKey();
                 if (!httpHeaderBlockContainsHeader(httpheaders, key))
                 {
-                    const char * value = traceHeaders->queryProp(key);
+                    const char * value = iter->queryPropValue();
                     if (!isEmptyString(value))
                         request.append(key).append(": ").append(value).append("\r\n");
                 }
diff --git a/ecl/eclagent/eclagent.cpp b/ecl/eclagent/eclagent.cpp
index d6c749a09c7..dc22e1f69dd 100644
--- a/ecl/eclagent/eclagent.cpp
+++ b/ecl/eclagent/eclagent.cpp
@@ -3613,7 +3613,7 @@ extern int HTHOR_API eclagent_main(int argc, const char *argv[], Owned<ILocalWor
             {
                 if (!query)
                     query.setown(createPTree("Query"));
-                const char *val = cmdLineArgs->queryProp(key);
+                const char *val = it->queryPropValue();
                 if (val[0]=='<')
                 {
                     Owned<IPropertyTree> valtree = createPTreeFromXMLString(val);
diff --git a/esp/bindings/SOAP/Platform/soapmessage.cpp b/esp/bindings/SOAP/Platform/soapmessage.cpp
index afbff7d681b..89768ab5c2e 100644
--- a/esp/bindings/SOAP/Platform/soapmessage.cpp
+++ b/esp/bindings/SOAP/Platform/soapmessage.cpp
@@ -33,7 +33,7 @@ static void serializeAttributes(StringBuffer& outbuf, IProperties* attrs)
         for (it->first(); it->isValid(); it->next())
         {
             const char* k = it->getPropKey();
-            const char* v = attrs->queryProp(k);
+            const char* v = it->queryPropValue();
             outbuf.append(' ').append(k).append("=\"");
             encodeUtf8XML(v,outbuf);
             outbuf.append('"');
@@ -171,7 +171,8 @@ void CRpcMessage::add_attr(const char * path, const char * name, const char * va
             for (piter->first(); piter->isValid(); piter->next())
             {
                 const char *propkey = piter->getPropKey();
-                par->add_attribute(propkey, attrs.queryProp(propkey));
+                const char *value = piter->queryPropValue();
+                par->add_attribute(propkey, value);
             }
         }
     }
@@ -181,7 +182,8 @@ void CRpcMessage::add_attr(const char * path, const char * name, const char * va
         for (piter->first(); piter->isValid(); piter->next())
         {
             const char *propkey = piter->getPropKey();
-            add_attribute(propkey, attrs.queryProp(propkey));
+            const char *value = piter->queryPropValue();
+            add_attribute(propkey, value);
         }
     }
 }
@@ -579,7 +581,7 @@ CSoapValue::CSoapValue(CSoapValue* soapvalue)
             m_attributes.setown(createProperties());
             Owned<IPropertyIterator> it = attrs->getIterator();
             for (it->first(); it->isValid(); it->next())
-                m_attributes->setProp(it->getPropKey(), attrs->queryProp(it->getPropKey()));
+                m_attributes->setProp(it->getPropKey(), it->queryPropValue());
         }
         m_is_array_element = soapvalue->m_is_array_element;
     }
@@ -1171,7 +1173,7 @@ void CSoapValue::add_value(const char* path, const char* ns, const char* name, c
         for (piter->first(); piter->isValid(); piter->next())
         {
             const char *propkey = piter->getPropKey();
-            sv->add_attribute(propkey, attrs.queryProp(propkey));
+            sv->add_attribute(propkey, piter->queryPropValue());
         }
     }
 }
diff --git a/esp/bindings/SOAP/Platform/soapparam.cpp b/esp/bindings/SOAP/Platform/soapparam.cpp
index 7356b881291..6d01fa5c70a 100644
--- a/esp/bindings/SOAP/Platform/soapparam.cpp
+++ b/esp/bindings/SOAP/Platform/soapparam.cpp
@@ -576,7 +576,7 @@ bool EspBaseArrayParam::unmarshall(IEspContext* ctx, IProperties &params, MapStr
             {
                 if (strlen(keyname)==taglen || !strncmp(keyname+taglen, "_rd_", 4))
                 {
-                    const char *finger = params.queryProp(iter->getPropKey());
+                    const char *finger = iter->queryPropValue();
                     StringBuffer itemval;
                     while (*finger)
                     {
@@ -610,7 +610,7 @@ bool EspBaseArrayParam::unmarshall(IEspContext* ctx, IProperties &params, MapStr
                 }
                 else if (strncmp(keyname+taglen, "_i", 2)==0)
                 {
-                    append(params.queryProp(iter->getPropKey()));
+                    append(iter->queryPropValue());
                     hasValue = true;
                 }
             }
diff --git a/esp/bindings/SOAP/ws_ecl_client/ws_ecl_client_bind.hpp b/esp/bindings/SOAP/ws_ecl_client/ws_ecl_client_bind.hpp
index 8f7d73bdcd5..0c67715f61a 100644
--- a/esp/bindings/SOAP/ws_ecl_client/ws_ecl_client_bind.hpp
+++ b/esp/bindings/SOAP/ws_ecl_client/ws_ecl_client_bind.hpp
@@ -344,7 +344,7 @@ class CClientRequestNode : implements IClientRequestNode, public CInterface
                 ForEach(*piter)
                 {
                     const char *propkey = piter->getPropKey();
-                    rpcMsg.add_value(path, "", propkey, "", m_params->queryProp(propkey), false);
+                    rpcMsg.add_value(path, "", propkey, "", piter->queryPropValue(), false);
                 }       
             }
 
diff --git a/esp/bindings/http/client/httpclient.cpp b/esp/bindings/http/client/httpclient.cpp
index 6f9968ea850..922b4c8d1eb 100644
--- a/esp/bindings/http/client/httpclient.cpp
+++ b/esp/bindings/http/client/httpclient.cpp
@@ -685,7 +685,7 @@ IHttpMessage *CHttpClient::sendRequestEx(const char* method, const char* content
             {
                 if (strieq(key, HTTP_HEADER_CONTENT_ENCODING) || strieq(key, HTTP_HEADER_TRANSFER_ENCODING))
                     alreadyEncoded = true;
-                const char *value = headers->queryProp(key);
+                const char *value = iter->queryPropValue();
                 if (value && *value)
                     httprequest->addHeader(key, value);
             }
diff --git a/esp/esdllib/esdl_def.cpp b/esp/esdllib/esdl_def.cpp
index 7325bcf9c8d..dce6db127f8 100644
--- a/esp/esdllib/esdl_def.cpp
+++ b/esp/esdllib/esdl_def.cpp
@@ -201,7 +201,7 @@ class EsdlDefObject : public CInterface
         ForEach(*it)
         {
             const char *name = it->getPropKey();
-            const char *val = props->queryProp(name);
+            const char *val = it->queryPropValue();
             xml.appendf(" %s=\"", name);
             encodeUtf8XML(val, xml);
             xml.append('\"');
diff --git a/esp/esdllib/esdl_def_helper.cpp b/esp/esdllib/esdl_def_helper.cpp
index 01355a41818..93075e575dc 100644
--- a/esp/esdllib/esdl_def_helper.cpp
+++ b/esp/esdllib/esdl_def_helper.cpp
@@ -346,7 +346,7 @@ void EsdlDefinitionHelper::loadTransformParams( EsdlXslTypeId xslId, IProperties
             const char *key = it->getPropKey();
             //set parameter in the XSL transform skipping over the @ prefix, if any
             const char* paramName = *key == '@' ? key+1 : key;
-            trans->setParameter(paramName, params->queryProp(key));
+            trans->setParameter(paramName, it->queryPropValue());
         }
     }
 
@@ -360,7 +360,7 @@ void EsdlDefinitionHelper::loadTransformParams( EsdlXslTypeId xslId, IProperties
             const char *key = it->getPropKey();
             //set parameter in the XSL transform skipping over the @ prefix, if any
             const char* paramName = *key == '@' ? key+1 : key;
-            trans->setParameter(paramName, overrideParams->queryProp(key));
+            trans->setParameter(paramName, it->queryPropValue());
         }
     }
 }
diff --git a/esp/esdllib/esdl_transformer2.cpp b/esp/esdllib/esdl_transformer2.cpp
index 744b7863a96..868321188da 100644
--- a/esp/esdllib/esdl_transformer2.cpp
+++ b/esp/esdllib/esdl_transformer2.cpp
@@ -224,7 +224,7 @@ void Esdl2Base::serialize_attributes(StringBuffer &out)
         {
             if (stricmp(key, "base_type") != 0)
             {
-                const char *value = m_def->queryProp(key);
+                const char *value = piter->queryPropValue();
                 if (value && *value)
                     out.appendf(" %s=\"%s\"", key, value);
             }
@@ -1311,7 +1311,7 @@ void Esdl2Request::addDefaults(IPropertyTree *req)
         const char *path = iter->getPropKey();
         if (!req->hasProp(path))
         {
-            const char *value = defvals->queryProp(path);
+            const char *value = iter->queryPropValue();
             ensurePTree(req, path);
             req->setProp(path, value);
         }
diff --git a/esp/esdlscriptlib/esdl_script.cpp b/esp/esdlscriptlib/esdl_script.cpp
index 979982bcfba..4c4c24b7f5c 100644
--- a/esp/esdlscriptlib/esdl_script.cpp
+++ b/esp/esdlscriptlib/esdl_script.cpp
@@ -3479,8 +3479,8 @@ class CEsdlCustomTransform : public CInterfaceOf<IEsdlCustomTransform>
             const char *prefix = ns->getPropKey();
             const char *existing = sourceContext->queryNamespace(prefix);
             savedNamespaces->setProp(prefix, isEmptyString(existing) ? "" : existing);
-            sourceContext->registerNamespace(prefix, namespaces->queryProp(prefix));
-            targetXpath->registerNamespace(prefix, namespaces->queryProp(prefix));
+            sourceContext->registerNamespace(prefix, ns->queryPropValue());
+            targetXpath->registerNamespace(prefix, ns->queryPropValue());
         }
         CXpathContextScope scope(sourceContext, "transform", XpathVariableScopeType::simple, savedNamespaces);
         if (!isEmptyString(target) && !streq(target, "."))
@@ -3607,7 +3607,7 @@ void processServiceAndMethodTransforms(IEsdlScriptContext * scriptCtx, std::init
         {
             const char *name = userPropIt->getPropKey();
             if (name && *name)
-                sourceContext->addInputValue(name, user->getProperty(name));
+                sourceContext->addInputValue(name, userPropIt->queryPropValue());
         }
 
         auto it = statusLabels.find(user->getStatus());
diff --git a/esp/platform/espcontext.cpp b/esp/platform/espcontext.cpp
index f860f96bde8..7cb4094b855 100755
--- a/esp/platform/espcontext.cpp
+++ b/esp/platform/espcontext.cpp
@@ -795,7 +795,7 @@ bool getUrlParams(IProperties *props, StringBuffer& params)
             params.append(key);
             if (stricmp(key,"ver_")==0)
                 hasVersion = true;
-            const char* v = props->queryProp(key);
+            const char* v = it->queryPropValue();
             if (v && *v)
                 params.appendf("=%s",v);
         }
diff --git a/esp/services/WsDeploy/WsDeployService.cpp b/esp/services/WsDeploy/WsDeployService.cpp
index 6d9a52637af..3268d6d635e 100644
--- a/esp/services/WsDeploy/WsDeployService.cpp
+++ b/esp/services/WsDeploy/WsDeployService.cpp
@@ -6405,7 +6405,7 @@ void CWsDeployFileInfo::initFileInfo(bool createOrOverwrite, bool bClearEnv)
     {
       StringBuffer prop;
       pParams->getProp(iter->getPropKey(), prop);
-      const char* val = pSettings->queryProp(iter->getPropKey());
+      const char* val = iter->queryPropValue();
 
       if (!val || strcmp(val, prop.str()))
       {
diff --git a/esp/services/ws_ecl/ws_ecl_service.cpp b/esp/services/ws_ecl/ws_ecl_service.cpp
index 7969b4ccf61..a444ce2d13c 100644
--- a/esp/services/ws_ecl/ws_ecl_service.cpp
+++ b/esp/services/ws_ecl/ws_ecl_service.cpp
@@ -595,7 +595,7 @@ void CWsEclBinding::xsltTransform(const char* xml, unsigned int len, const char*
             const char *key = it->getPropKey();
             //set parameter in the XSL transform skipping over the @ prefix, if any
             const char* paramName = *key == '@' ? key+1 : key;
-            trans->setParameter(paramName, StringBuffer().append('\'').append(params->queryProp(key)).append('\'').str());
+            trans->setParameter(paramName, StringBuffer().append('\'').append(it->queryPropValue()).append('\'').str());
         }
     }
 
diff --git a/esp/services/ws_esdlconfig/ws_esdlconfigservice.cpp b/esp/services/ws_esdlconfig/ws_esdlconfigservice.cpp
index d4ec4c0432d..da81cfc31a4 100644
--- a/esp/services/ws_esdlconfig/ws_esdlconfigservice.cpp
+++ b/esp/services/ws_esdlconfig/ws_esdlconfigservice.cpp
@@ -265,7 +265,7 @@ void CWsESDLConfigEx::wrapWithDefinitionElement(IEsdlDefinitionInfo* defInfo, St
     ForEach(*iter)
     {
         const char* name = iter->getPropKey();
-        const char* val = metadata.queryProp(name);
+        const char* val = iter->queryPropValue();
         // skip the leading @ in the property name
         definitionElement.appendf(" %s=\"%s\"", &name[1], val);
     }
diff --git a/esp/services/ws_fs/ws_fsBinding.cpp b/esp/services/ws_fs/ws_fsBinding.cpp
index 6693bd96cf6..fb5ed95c7df 100644
--- a/esp/services/ws_fs/ws_fsBinding.cpp
+++ b/esp/services/ws_fs/ws_fsBinding.cpp
@@ -378,7 +378,7 @@ void CFileSpraySoapBindingEx::xsltTransform(const char* xml, const char* sheet,
             const char *key = it->getPropKey();
             //set parameter in the XSL transform skipping over the @ prefix, if any
             const char* paramName = *key == '@' ? key+1 : key;
-            trans->setParameter(paramName, StringBuffer().append('\'').append(params->queryProp(key)).append('\'').str());
+            trans->setParameter(paramName, StringBuffer().append('\'').append(it->queryPropValue()).append('\'').str());
         }
     }
 
diff --git a/esp/services/ws_workunits/ws_wuresult.cpp b/esp/services/ws_workunits/ws_wuresult.cpp
index a4ab8e5204d..314ce18e34e 100644
--- a/esp/services/ws_workunits/ws_wuresult.cpp
+++ b/esp/services/ws_workunits/ws_wuresult.cpp
@@ -223,7 +223,7 @@ void CWsWuResultOutHelper::readFilterByReq()
     ForEach(*iter)
     {
         const char* keyname = iter->getPropKey();
-        const char* keyValue = reqParams->queryProp(iter->getPropKey());
+        const char* keyValue = iter->queryPropValue();
         if (isEmptyString(keyname) || isEmptyString(keyValue) || strncmp(keyname, "FilterBys", 9))
             continue;
 
diff --git a/system/jlib/jprop.cpp b/system/jlib/jprop.cpp
index 2ff7b961b75..339f3dc3119 100644
--- a/system/jlib/jprop.cpp
+++ b/system/jlib/jprop.cpp
@@ -35,35 +35,32 @@ template <class PTYPE, class PITER>
 class PropertyIteratorOf : implements PITER, public CInterface
 {
 protected:
-    HashIterator *piter;
     const HashTable &properties;
+    HashIterator piter;
 
 public:
     IMPLEMENT_IINTERFACE; 
 
-    PropertyIteratorOf(const HashTable &_properties) : properties(_properties)
+    PropertyIteratorOf(const HashTable &_properties) : properties(_properties), piter(properties)
     {
         properties.Link();
-        piter = new HashIterator(properties);
     }
     ~PropertyIteratorOf()
     {
         properties.Release();
-        piter->Release();
     }
-    virtual bool first()
+    virtual bool first() override
     {
-        return piter->first();
+        return piter.first();
     }
-    virtual bool next()
+    virtual bool next() override
     {
-        return piter->next();
+        return piter.next();
     }
-    virtual bool isValid()
+    virtual bool isValid() override
     {
-        return piter->isValid();
+        return piter.isValid();
     }
-    virtual PTYPE getPropKey() = 0;
 };
 
 typedef IPropertyIterator char_ptrIPropertyIterator;
@@ -71,12 +68,17 @@ class char_ptrPropertyIterator : public PropertyIteratorOf<const char *, char_pt
 {
 public:
     char_ptrPropertyIterator(const HashTable &_properties) : PropertyIteratorOf<const char *, char_ptrIPropertyIterator>(_properties) { }
-    virtual const char *getPropKey()
+    virtual const char *getPropKey() const override
     {
-        IMapping &cur = piter->query();
+        IMapping &cur = piter.query();
         const char *key = (const char *) (cur.getKey());
         return key;
     }
+    virtual const char *queryPropValue() const override
+    {
+        IMapping &cur = piter.query();
+        return StringAttrMapping::mapToValue(&cur)->str();
+    }
 };
 
 template <class PTYPE, class MAPPING, class IPROP, class IPROPITER, class PROPITER>
diff --git a/system/jlib/jprop.hpp b/system/jlib/jprop.hpp
index fdbb24e9ee3..a54d266355b 100644
--- a/system/jlib/jprop.hpp
+++ b/system/jlib/jprop.hpp
@@ -32,7 +32,8 @@ interface jlib_decl IPropertyIteratorOf : extends IInterface
     virtual bool first() = 0;
     virtual bool next() = 0;
     virtual bool isValid() = 0;
-    virtual PTYPE getPropKey() = 0;
+    virtual PTYPE getPropKey() const = 0;
+    virtual const char * queryPropValue() const = 0;
 };
 
 template <class PTYPE, class PITER>
@@ -64,7 +65,6 @@ interface jlib_decl IPropertiesOf : extends serializable
 #endif
 
 interface IPropertyIterator : public IPropertyIteratorOf<char_ptr> { };
-interface IAtomPropertyIterator : public IPropertyIteratorOf<IAtom *> { };
 interface IProperties : public IPropertiesOf<char_ptr, IPropertyIterator> { };
 
 #ifdef _MSC_VER
diff --git a/system/jlib/jptree.cpp b/system/jlib/jptree.cpp
index 4b314e3f5b3..82ee2685da5 100644
--- a/system/jlib/jptree.cpp
+++ b/system/jlib/jptree.cpp
@@ -8302,7 +8302,7 @@ IPropertyTree *createPTreeFromHttpParameters(const char *nameWithAttrs, IPropert
             continue;
         if (skipLeadingDotParameters && key.charAt(0)=='.')
             continue;
-        const char *value = parameters->queryProp(key);
+        const char *value = iter->queryPropValue();
         if (!value || !*value)
             continue;
         ensureHttpParameter(content, key, value);
@@ -8525,10 +8525,9 @@ void applyProperties(IPropertyTree * target, const IProperties * source)
     Owned<IPropertyIterator> iter = source->getIterator();
     ForEach(*iter)
     {
-        StringBuffer value;
         const char * name = iter->getPropKey();
-        source->getProp(name, value);
-        target->setProp(name, value.str());
+        const char * value = iter->queryPropValue();
+        target->setProp(name, value);
     }
 }
 
diff --git a/system/jlib/jsuperhash.hpp b/system/jlib/jsuperhash.hpp
index 9936e86112f..8806ad52993 100644
--- a/system/jlib/jsuperhash.hpp
+++ b/system/jlib/jsuperhash.hpp
@@ -229,7 +229,7 @@ class jlib_decl SuperHashIterator : public CInterface
       { if (cur) cur = table.next(cur); return (cur != NULL); }
  
 protected:
-    void *           queryPointer() { assertex(cur); return cur; }
+    void *           queryPointer() const { assertex(cur); return cur; }
 
 private:
     bool linkTable;
@@ -242,7 +242,7 @@ class SuperHashIteratorOf : public SuperHashIterator
 {
   public:
     SuperHashIteratorOf(const SuperHashTable & _table, bool linkTable=true) : SuperHashIterator(_table, linkTable) {}
-    ET &             query()
+    ET &             query() const
       { return *(static_cast<ET *>(queryPointer())); }
 };
 
diff --git a/system/jlib/jtrace.cpp b/system/jlib/jtrace.cpp
index b45b67aed8e..c5828eb1531 100644
--- a/system/jlib/jtrace.cpp
+++ b/system/jlib/jtrace.cpp
@@ -60,7 +60,7 @@ class CHPCCHttpTextMapCarrier : public opentelemetry::context::propagation::Text
             ForEach(*iter)
             {
                 const char * key = iter->getPropKey();
-                const char * val = httpHeaders->queryProp(key);
+                const char * val = iter->queryPropValue();
                 this->httpHeaders->setProp(key, val);
             }
         }
@@ -182,8 +182,7 @@ class CSpan : public CInterfaceOf<ISpan>
         ForEach(*iter)
         {
             const char * key = iter->getPropKey();
-            if (!isEmptyString(key))
-                setSpanAttribute(key, attributes->queryProp(key));
+            setSpanAttribute(key, iter->queryPropValue());
         }
     }