diff --git a/CMakeLists.txt b/CMakeLists.txt
index de81fbe..25f5ff5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -95,3 +95,4 @@ add_subdirectory(doc)
 # Packaging utility
 include(HepMCUseCpack)
 
+install(FILES modulemap/hepmc.modulemap DESTINATION "include")
diff --git a/HepMC/PdfInfo.h b/HepMC/PdfInfo.h
index a554c22..f5009a0 100644
--- a/HepMC/PdfInfo.h
+++ b/HepMC/PdfInfo.h
@@ -8,6 +8,10 @@
 // Additional PDF information
 //////////////////////////////////////////////////////////////////////////
 
+#include <ostream>
+#include <istream>
+#include <algorithm>
+
 namespace HepMC {
 
 //! The PdfInfo class stores PDF information
diff --git a/HepMC/TempParticleMap.h b/HepMC/TempParticleMap.h
index 180e006..1202c4c 100644
--- a/HepMC/TempParticleMap.h
+++ b/HepMC/TempParticleMap.h
@@ -8,11 +8,10 @@
 // Used by IO classes
 //////////////////////////////////////////////////////////////////////////
 
+#include "HepMC/GenParticle.h"
 #include <map>
 
-namespace HepMC {
-
-    class GenParticle;
+namespace HepMC {  
 
     //! TempParticleMap is a temporary GenParticle* container used during input.
 
diff --git a/modulemap/hepmc.modulemap b/modulemap/hepmc.modulemap
new file mode 100644
index 0000000..599fb94
--- /dev/null
+++ b/modulemap/hepmc.modulemap
@@ -0,0 +1,6 @@
+module HepMC {
+  export *
+  requires cplusplus
+  umbrella "HepMC"
+  module * { export *}
+}