diff --git a/source/blender/imbuf/intern/openexr/openexr_api.cpp b/source/blender/imbuf/intern/openexr/openexr_api.cpp
index 34afdda0177..26aab29b8dd 100644
--- a/source/blender/imbuf/intern/openexr/openexr_api.cpp
+++ b/source/blender/imbuf/intern/openexr/openexr_api.cpp
@@ -153,7 +153,7 @@ void Mem_IStream::clear()
 
 /* File Input Stream */
 
-class IFileStream : public IStream
+class IFileStream : public Imf::IStream
 {
 public:
 	IFileStream(const char *filename)