SDL_rtf 1.3 build errors

Today I installed SDL-1.3, and SDL_ttf and SDL_rtf.

ran:
sh autogen.sh
./configure
make

for all of them.

SDL_rtf shows errors during make:

Code:
gcc -DPACKAGE_NAME="" -DPACKAGE_TARNAME="" -DPACKAGE_VERSION="" -DPACKAGE_STRING="" -DPACKAGE_BUGREPORT="" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -DLT_OBJDIR=".libs/" -DPACKAGE=“SDL_rtf” -DVERSION=“0.1.1” -I. -g -O2 -D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL -MT showrtf.o -MD -MP -MF .deps/showrtf.Tpo -c -o showrtf.o showrtf.c
showrtf.c:31:21: error: SDL_ttf.h: No such file or directory

Notice the -I/usr/include/SDL. It should be -I/usr/local/include/SDL

I had to change the Makefile settings for CFLAGS and SDL_FLAGS from this:

Code:
-I/usr/include/SDL

to this:

Code:
-I$(libSDL_rtfincludedir)

and then SDL_rtf would compile.

Is it a bug? Or is there something I should be feeding to configure?

BTW, I have an existing installation of SDL-1.2 that is installed under /usr.

.