diff --git a/prism/ext/lp_solve_5.5_java/lib/build b/prism/ext/lp_solve_5.5_java/lib/build
index 3d4c7314..070a6c66 100755
--- a/prism/ext/lp_solve_5.5_java/lib/build
+++ b/prism/ext/lp_solve_5.5_java/lib/build
@@ -22,12 +22,22 @@ echo DIR $JDK_DIR
 
 c=g++
 
+if [ "$ARCH" = "" ]; then
+	CFLAGS = -m32
+fi
+if [ "$ARCH" = "amd64" ]; then
+	CFLAGS = -m64 -fPIC -DPIC
+fi
+if [ "$ARCH" = "" ]; then
+	CFLAGS = -fPIC -DPIC
+fi
+
 #determine platform (32/64 bit)
 >/tmp/platform.c
 echo '#include <stdlib.h>'>>/tmp/platform.c
 echo '#include <stdio.h>'>>/tmp/platform.c
 echo 'main(){printf("ux%d", (int) (sizeof(void *)*8));}'>>/tmp/platform.c
-$c /tmp/platform.c -o /tmp/platform
+$c $CFLAGS /tmp/platform.c -o /tmp/platform
 PLATFORM=`/tmp/platform`
 rm /tmp/platform /tmp/platform.c >/dev/null 2>&1
 
@@ -38,5 +48,5 @@ mkdir $PLATFORM >/dev/null 2>&1
 SRC_DIR=../src/c
 INCL="-I $JDK_DIR/include -I $JDK_DIR/include/linux -I $LPSOLVE_DIR -I $SRC_DIR"
 
-$c -fpic $INCL -c $SRC_DIR/lpsolve5j.cpp
-$c -shared -Wl,-soname,liblpsolve55j.so -o $PLATFORM/liblpsolve55j.so lpsolve5j.o -L$LPSOLVE_LIB_DIR -lc -llpsolve55
+$c $CFLAGS $INCL -c $SRC_DIR/lpsolve5j.cpp
+$c $CFLAGS -shared -Wl,-soname,liblpsolve55j.so -o $PLATFORM/liblpsolve55j.so lpsolve5j.o -L$LPSOLVE_LIB_DIR -lc -llpsolve55