diff --git a/prism/ext/lp_solve_5.5_java/lib/mac/liblpsolve55j.jnilib b/prism/ext/lp_solve_5.5_java/lib/mac/liblpsolve55j.jnilib
index 41800ea6..47ff33b2 100755
Binary files a/prism/ext/lp_solve_5.5_java/lib/mac/liblpsolve55j.jnilib and b/prism/ext/lp_solve_5.5_java/lib/mac/liblpsolve55j.jnilib differ
diff --git a/prism/ext/lpsolve55/Makefile b/prism/ext/lpsolve55/Makefile
index be07eae0..25e76b1e 100644
--- a/prism/ext/lpsolve55/Makefile
+++ b/prism/ext/lpsolve55/Makefile
@@ -33,9 +33,13 @@ checks:
 	fi; 
 
 ../../lib/$(LIBPREFIX)lpsolve55$(LIBSUFFIX):
-	@(cd src/lp_solve_5.5/lpsolve55 && \
-	c=$(C) sh $(LPSOLVE55_BUILD) \
-	) && mv lib/$(LIBPREFIX)lpsolve55$(LIBSUFFIX) ../../lib
+	@if [ "$(OSTYPE)" = "cygwin" ]; then \
+	(cp bin/win32/*dll ../../lib) \
+	else \
+	(cd src/lp_solve_5.5/lpsolve55 && \
+	c=$(C) sh -x $(LPSOLVE55_BUILD) \
+	) && mv lib/$(LIBPREFIX)lpsolve55$(LIBSUFFIX) ../../lib \
+	fi;
 
 clean: checks
 	rm -f lib/$(LIBPREFIX)lpsolve55$(LIBSUFFIX) ../../lib/$(LIBPREFIX)lpsolve55$(LIBSUFFIX)