diff --git a/GeneratorInterface/LHEInterface/interface/TestWeightInfo.h b/GeneratorInterface/LHEInterface/interface/TestWeightInfo.h
index efb0162bb8063..7e386bf1cd4ce 100644
--- a/GeneratorInterface/LHEInterface/interface/TestWeightInfo.h
+++ b/GeneratorInterface/LHEInterface/interface/TestWeightInfo.h
@@ -1,4 +1,5 @@
 #include "SimDataFormats/GeneratorProducts/interface/WeightGroupInfo.h"
+#include "SimDataFormats/GeneratorProducts/interface/PdfWeightGroupInfo.h"
 #include <regex>
 
 std::string parseId(std::string label) {
@@ -993,7 +994,7 @@ edm::OwnVector<gen::WeightGroupInfo> getExamplePdfWeights() {
     int counter = 8;
     for (const auto& entry : entries) {
         if (entry.find("<weightgroup") != std::string::npos) {
-            pdfWeights.push_back(new gen::WeightGroupInfo(entry));
+            pdfWeights.push_back(new gen::PdfWeightGroupInfo(entry));
         }
         else if (entry.find("</weightgroup") == std::string::npos) {
             auto& currentSet = pdfWeights.back();
diff --git a/SimDataFormats/GeneratorProducts/interface/PdfWeightGroupInfo.h b/SimDataFormats/GeneratorProducts/interface/PdfWeightGroupInfo.h
new file mode 100644
index 0000000000000..3071bf7aa0f4e
--- /dev/null
+++ b/SimDataFormats/GeneratorProducts/interface/PdfWeightGroupInfo.h
@@ -0,0 +1,44 @@
+#ifndef SimDataFormats_GeneratorProducts_PdfWeightGroupInfo_h
+#define SimDataFormats_GeneratorProducts_PdfWeightGroupInfo_h
+
+#include "SimDataFormats/GeneratorProducts/interface/WeightGroupInfo.h"
+
+namespace gen {
+    enum PdfUncertaintyType {
+        kHessianUnc,
+        kMonteCarloUnc,
+        kUnknownUnc,
+    };
+
+    class PdfWeightGroupInfo : public WeightGroupInfo {
+        private:
+            PdfUncertaintyType uncertaintyType_;
+            bool hasAlphasVars_;
+            int alphasUpIndex_;
+            int alphasDownIndex_;
+        public:
+            PdfWeightGroupInfo() : WeightGroupInfo() { weightType_ = kPdfWeights; }
+	        PdfWeightGroupInfo(std::string header, std::string name) : 
+                WeightGroupInfo(header, name) { weightType_ = kPdfWeights; } 
+	        PdfWeightGroupInfo(std::string header) : 
+                WeightGroupInfo(header) { weightType_ = kPdfWeights; } 
+            PdfWeightGroupInfo(const PdfWeightGroupInfo &other) {
+                copy(other);
+            }
+            virtual ~PdfWeightGroupInfo() override {};
+            void copy(const PdfWeightGroupInfo &other);
+            PdfWeightGroupInfo* clone() const;
+
+            void setUncertaintyType(PdfUncertaintyType uncertaintyType) { uncertaintyType_ = uncertaintyType; }
+            void setHasAlphasVariations(bool hasAlphasVars) { hasAlphasVars_ = hasAlphasVars; }
+            void setAlphasUpIndex(int alphasUpIndex) { alphasUpIndex_ = alphasUpIndex; }
+            void setAlphasDownIndex(int alphasDownIndex) { alphasDownIndex_ = alphasDownIndex; }
+            PdfUncertaintyType uncertaintyType() const { return uncertaintyType_; }
+            bool hasAlphasVariations() const { return hasAlphasVars_; }
+            int alphasUpIndex() const { return alphasUpIndex_; }
+            int alphasDownIndex() const { return alphasDownIndex_; }
+    };
+}
+
+#endif // SimDataFormats_GeneratorProducts_PdfWeightGroupInfo_h
+
diff --git a/SimDataFormats/GeneratorProducts/interface/WeightGroupInfo.h b/SimDataFormats/GeneratorProducts/interface/WeightGroupInfo.h
index 364a43937f2fa..a8d8bd0585248 100644
--- a/SimDataFormats/GeneratorProducts/interface/WeightGroupInfo.h
+++ b/SimDataFormats/GeneratorProducts/interface/WeightGroupInfo.h
@@ -38,8 +38,8 @@ namespace gen {
                 copy(other);
                 return *this; 
             }
+            virtual ~WeightGroupInfo() {};
             void copy(const WeightGroupInfo &other);
-
             WeightGroupInfo* clone() const;
             WeightMetaInfo weightMetaInfo(int weightEntry);
             WeightMetaInfo weightMetaInfo(std::string wgtId);
@@ -63,7 +63,7 @@ namespace gen {
             int firstId() const { return firstId_; }
             int lastId() const { return lastId_; }
 
-        private:
+        protected:
             std::string headerEntry_;
             std::string name_;
             WeightType weightType_;
diff --git a/SimDataFormats/GeneratorProducts/src/PdfWeightGroupInfo.cc b/SimDataFormats/GeneratorProducts/src/PdfWeightGroupInfo.cc
new file mode 100644
index 0000000000000..f78cb5a1850d2
--- /dev/null
+++ b/SimDataFormats/GeneratorProducts/src/PdfWeightGroupInfo.cc
@@ -0,0 +1,16 @@
+#include <string>
+#include "SimDataFormats/GeneratorProducts/interface/PdfWeightGroupInfo.h"
+
+namespace gen {
+    void PdfWeightGroupInfo::copy(const PdfWeightGroupInfo &other) {
+        uncertaintyType_ = other.uncertaintyType();
+        hasAlphasVars_ = other.hasAlphasVariations();
+        alphasUpIndex_ = other.alphasDownIndex();
+        alphasDownIndex_ = other.alphasDownIndex();
+        WeightGroupInfo::copy(other);
+    }
+
+    PdfWeightGroupInfo* PdfWeightGroupInfo::clone() const {
+        return new PdfWeightGroupInfo(*this);
+    }
+}
diff --git a/SimDataFormats/GeneratorProducts/src/classes_def.xml b/SimDataFormats/GeneratorProducts/src/classes_def.xml
index 7e6ae7131b9c8..6e36f2de18394 100644
--- a/SimDataFormats/GeneratorProducts/src/classes_def.xml
+++ b/SimDataFormats/GeneratorProducts/src/classes_def.xml
@@ -223,9 +223,8 @@
  <class name="gen::WeightsInfo" ClassVersion="10">
   <version ClassVersion="10" checksum="2663143460"/>
  </class>
- <class name="gen::WeightGroupInfo" ClassVersion="6">
-  <version ClassVersion="6" checksum="1055618343"/>
- </class>
+ <class name="gen::WeightGroupInfo"/>
+ <class name="gen::PdfWeightGroupInfo"/>
  <class name="gen::WeightMetaInfo"/>
  <class name="std::vector<gen::WeightsInfo>"/>
  <class name="std::vector<gen::WeightGroupInfo>"/>