diff --git a/build/rules/global b/build/rules/global
index 0a582a1c5..f972e5ce6 100644
--- a/build/rules/global
+++ b/build/rules/global
@@ -68,7 +68,10 @@ endif
 #
 POCO_HOST_OSNAME = $(shell uname)
 ifeq ($(findstring CYGWIN,$(POCO_HOST_OSNAME)),CYGWIN)
-POCO_HOST_OSNAME = CYGWIN
+ifeq ($(findstring x86_64,$(POCO_HOST_OSNAME)),x86_64)
+OSARCH_64BITS = 1
+endif
+POCO_HOST_OSNAME = Cygwin
 endif
 
 ifeq ($(findstring MINGW,$(POCO_HOST_OSNAME)),MINGW)
@@ -161,6 +164,9 @@ LIB64SUFFIX = $(if $(filter $(OSARCH),x86_64 sparc64 ppc64),64,)
 else ifneq ($(DEBIANISH),)
 LIB64SUFFIX = $(if $(filter $(OSARCH),x86_64 sparc64 ppc64),/x86_64-linux-gnu,)
 endif
+ifeq ($(findstring Cygwin,$(POCO_HOST_OSNAME)),Cygwin)
+LIB64SUFFIX = $(if $(filter $(OSARCH),x86_64),64,)
+endif
 
 # Default static lib extension
 STATICLIBLINKEXT = .a