diff --git a/mk/lib.mk b/mk/lib.mk
index 56e162d5..f7c8c6b3 100644
--- a/mk/lib.mk
+++ b/mk/lib.mk
@@ -29,8 +29,13 @@ mandir ?= $(prefix)/share/man
 BUILD_SHARED_LIBS ?= 1
 
 ifeq ($(BUILD_SHARED_LIBS), 1)
-  GLOBAL_CFLAGS += -fPIC
-  GLOBAL_CXXFLAGS += -fPIC
+  ifeq (CYGWIN,$(findstring CYGWIN,$(OS)))
+    GLOBAL_CFLAGS += -U__STRICT_ANSI__
+    GLOBAL_CXXFLAGS += -U__STRICT_ANSI__
+  else
+    GLOBAL_CFLAGS += -fPIC
+    GLOBAL_CXXFLAGS += -fPIC
+  endif
   ifneq ($(OS), Darwin)
    ifneq ($(OS), SunOS)
     GLOBAL_LDFLAGS += -Wl,--no-copy-dt-needed-entries