diff --git a/GNUmakefiles/LibIncludes b/GNUmakefiles/LibIncludes
index c5c2e8501b11f225668a8a557e9d88d1617f8717..55e3ba583deec6f263b77b22c32200f58f7091b4 100644
--- a/GNUmakefiles/LibIncludes
+++ b/GNUmakefiles/LibIncludes
@@ -12,6 +12,7 @@ INCLUDED_LIBINCLUDES = YES
 OSINC      = -I${LIBDIR}/OSLib/Core -I${LIBDIR}/OSLib/Computer -I${LIBDIR}/OSLib/User -I${LIBDIR}/OSLib/Toolbox -I${LIBDIR}/OSLib/Core/oslib -I${LIBDIR}/OSLib/Computer/oslib -I${LIBDIR}/OSLib/User/oslib -I${LIBDIR}/OSLib/Toolbox/oslib
 # Deprecated synonym
 INCLUDE_OSLIB = ${OSINC}
+TBOXINC    = -I${LIBDIR}/tboxlibs
 TCPIPINC   = -I${LIBDIR}/TCPIPLibs
 
 # EOF
diff --git a/Makefiles/LibIncludes b/Makefiles/LibIncludes
index 496d33ab837f7f18713aac283e9af5caae6742ae..379ed81ebc4268a8d3f4f10e0271d4278100fd43 100644
--- a/Makefiles/LibIncludes
+++ b/Makefiles/LibIncludes
@@ -12,6 +12,7 @@ INCLUDED_LIBINCLUDES = YES
 OSINC      = -IOS:
 # Deprecated synonym
 INCLUDE_OSLIB = ${OSINC}
+TBOXINC    = -Itbox:
 TCPIPINC   = -ITCPIPLibs:
 
 # EOF