diff --git a/configure/os/CONFIG.Common.cygwin-x86 b/configure/os/CONFIG.Common.cygwin-x86
index c4b130efd..36c083a01 100644
--- a/configure/os/CONFIG.Common.cygwin-x86
+++ b/configure/os/CONFIG.Common.cygwin-x86
@@ -30,5 +30,8 @@ OP_SYS_CPPFLAGS += -DCYGWIN32 -U_WIN32
 # Set runtime path for shared libraries
 RUNTIME_LDFLAGS = $(SHRLIB_SEARCH_FULLPATHDIRS:%=-Wl,-rpath,%)
 
+#  Definitions used when COMMANDLINE_LIBRARY is READLINE
+INCLUDES_READLINE = -I$(GNU_DIR)/include
+LDFLAGS_READLINE += -L$(GNU_DIR)/lib
 LDLIBS_READLINE = -lcygreadline5 -lcygcurses7
 
diff --git a/configure/os/CONFIG_SITE.cygwin-x86.cygwin-x86 b/configure/os/CONFIG_SITE.cygwin-x86.cygwin-x86
index 9703f5c37..309f38a8b 100644
--- a/configure/os/CONFIG_SITE.cygwin-x86.cygwin-x86
+++ b/configure/os/CONFIG_SITE.cygwin-x86.cygwin-x86
@@ -6,5 +6,6 @@
 # Site override definitions for cygwin-x86 host - cygwin-x86 target builds
 #-------------------------------------------------------
  
-##GNU_DIR=C:/cygwin
+#  GNU_DIR used when COMMANDLINE_LIBRARY is READLINE
+GNU_DIR=C:/cygwin