diff --git a/Source/BinaryCStream.m b/Source/BinaryCStream.m
index 0d0a406e7..1abff7c28 100644
--- a/Source/BinaryCStream.m
+++ b/Source/BinaryCStream.m
@@ -29,6 +29,7 @@
 #include <gnustep/base/MallocAddress.h>
 #include <Foundation/NSException.h>
 #include <math.h>
+#include <values.h>		// This gets BITSPERBYTE on Solaris
 
 #define DEFAULT_FORMAT_VERSION 0