diff --git a/Makefile.detect b/Makefile.detect
index 37dba2de..813b8d28 100644
--- a/Makefile.detect
+++ b/Makefile.detect
@@ -72,10 +72,10 @@ EXE = .exe
 CC = gcc
 CLIBFLAGS =
 CLINKFLAGS = -shared
-CPPFLAGS += -DSEXP_USE_STRING_STREAMS=0 -DBUILDING_DLL
+CPPFLAGS += -DSEXP_USE_STRING_STREAMS=0 -DSEXP_USE_GREEN_THREADS=0 -DBUILDING_DLL
 LIBCHIBI_FLAGS = -Wl,--out-implib,libchibi-scheme$(SO).a
 STATICFLAGS = -DSEXP_USE_DL=0
-LIBDL = 
+LIBDL = -lws2_32
 else
 ifeq ($(PLATFORM),cygwin)
 SO  = .dll