diff -rup a/GDALmake.opt.in b/GDALmake.opt.in
--- a/GDALmake.opt.in	2016-01-26 16:21:51.000000000 +0100
+++ b/GDALmake.opt.in	2016-02-23 12:25:16.102779881 +0100
@@ -66,7 +66,7 @@ INST_DOCS	=	@exec_prefix@/doc
 INST_MAN	=	@mandir@
 INST_HTML	=	$(HOME)/www/gdal
 
-CPPFLAGS	= @CPPFLAGS@ -I$(GDAL_ROOT)/port @EXTRA_INCLUDES@ -DGDAL_COMPILATION
+CPPFLAGS	= @CPPFLAGS@ -I$(GDAL_ROOT)/port -I$(GDAL_ROOT)/gcore @EXTRA_INCLUDES@ -DGDAL_COMPILATION
 CFLAGS		= @CFLAGS@ @C_WFLAGS@ $(USER_DEFS)
 CXXFLAGS	= @CXXFLAGS@ @CXX_WFLAGS@ $(USER_DEFS)
 LDFLAGS     = @LDFLAGS@