diff --git a/config/CONFIG.Host.Borland b/config/CONFIG.Host.Borland
index e121dd4d3..cc5aa357d 100644
--- a/config/CONFIG.Host.Borland
+++ b/config/CONFIG.Host.Borland
@@ -133,7 +133,7 @@ OP_SYS_LDLIBS =
 #
 # specify dll .def file only if it exists
 #
-DLL_DEF_FLAG = $(addprefix /def:,$(wildcard ../$(LIBRARY).def))
+DLL_DEF_FLAG = $(subst /,\\,$(wildcard ../$(LIBRARY).def))
 
 #	HOST_OPT_FLAGS is part of CFLAGS/CXXFLAGS,
 #	which in turn are used in COMPILE.c[c]