diff --git a/src/error.cpp b/src/error.cpp
index 342707204..56e852a2b 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -124,7 +124,7 @@ struct exit_code_category final : public error_category
 #            if defined(SIGPROF)
                     case SIGPROF: return "SIGPROF:   Profiling timer expired";
 #            endif
-#            if defined(SIGPWR)
+#            if defined(SIGPWR) && !defined(__CYGWIN__) // cygwin defines it as SIGLOST
                     case SIGPWR: return "SIGPWR:    Power failure (System V)";
 #            endif
 #            if defined(SIGQUIT)
diff --git a/src/ext/env.cpp b/src/ext/env.cpp
index 41fcc9acd..5a9e07726 100644
--- a/src/ext/env.cpp
+++ b/src/ext/env.cpp
@@ -137,7 +137,7 @@ const environment::char_type * dereference(native_env_iterator iterator)
     return iterator;
 }
 
-#elif (defined(__APPLE___) || defined(__MACH__)) || defined(__FreeBSD__) || defined(__DragonFly__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__sun)
+#elif (defined(__APPLE___) || defined(__MACH__)) || defined(__FreeBSD__) || defined(__DragonFly__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__sun) || defined(__CYGWIN__)
 
 void native_env_handle_deleter::operator()(native_env_handle_type h) const
 {
@@ -309,7 +309,7 @@ env_view env(boost::process::v2::pid_type pid, error_code & ec)
     return ev;
 }
 
-#elif (defined(__linux__) || defined(__ANDROID__)) || defined(__gnu_hurd__)
+#elif (defined(__linux__) || defined(__ANDROID__)) || defined(__gnu_hurd__) || defined(__CYGWIN__)
 
 env_view env(boost::process::v2::pid_type pid, error_code & ec)
 {