diff --git a/DDCore/src/parsers/GrammarsV2.h b/DDCore/src/parsers/GrammarsV2.h
index fcbc66f58836a2bb03993f3ac91bf0b978f59ccf..d0b85de926be48fb660ff170b9edfeb3941492d5 100644
--- a/DDCore/src/parsers/GrammarsV2.h
+++ b/DDCore/src/parsers/GrammarsV2.h
@@ -32,6 +32,7 @@
 //==============================================================================
 #ifdef __GNUC__
 #undef __GNUC__
+// Boost spits out an error if __GNUC__ is defined!
 #include <boost/spirit/include/qi.hpp>
 #define __GNUC__
 #else
diff --git a/DDG4/include/DDG4/IoStreams.h b/DDG4/include/DDG4/IoStreams.h
index c18c73a87b06a0443e62c807e3e3caa736ed656d..2d1ce26be2e629762904f08cf1464f03c6671105 100644
--- a/DDG4/include/DDG4/IoStreams.h
+++ b/DDG4/include/DDG4/IoStreams.h
@@ -22,12 +22,20 @@
 #pragma GCC diagnostic ignored "-Wshadow" // Code that causes warning goes here
 #endif
 
+#ifdef __GNUC__
+#undef __GNUC__
+// Boost spits out an error if __GNUC__ is defined!
+#include <boost/iostreams/stream.hpp>
+#define __GNUC__
+#else
+#include <boost/iostreams/stream.hpp>
+#endif
+
 // booost iostreams include files
 #include <boost/iostreams/categories.hpp>
 #include <boost/iostreams/detail/ios.hpp>
 #include <boost/iostreams/detail/path.hpp>
 #include <boost/iostreams/positioning.hpp>
-#include <boost/iostreams/stream.hpp>
 
 // Forward declarations
 class TFile;