Index: include/__config
===================================================================
--- include/__config
+++ include/__config
@@ -325,6 +325,9 @@
 #if defined(__FreeBSD__)
 #define _LIBCPP_HAS_QUICK_EXIT
 #define _LIBCPP_HAS_C11_FEATURES
+#elif defined(__Fuchsia__)
+#define _LIBCPP_HAS_QUICK_EXIT
+#define _LIBCPP_HAS_C11_FEATURES
 #elif defined(__linux__)
 #if !defined(_LIBCPP_HAS_MUSL_LIBC)
 #if __GLIBC_PREREQ(2, 15) || defined(__BIONIC__)
@@ -832,6 +835,7 @@
     !defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && \
     !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
 # if defined(__FreeBSD__) || \
+    defined(__Fuchsia__) || \
     defined(__NetBSD__) || \
     defined(__linux__) || \
     defined(__APPLE__) || \
Index: src/include/config_elast.h
===================================================================
--- src/include/config_elast.h
+++ src/include/config_elast.h
@@ -20,6 +20,8 @@
 #define _LIBCPP_ELAST ELAST
 #elif defined(_NEWLIB_VERSION)
 #define _LIBCPP_ELAST __ELASTERROR
+#elif defined(__Fuchsia__)
+// No _LIBCPP_ELAST needed on Fuchsia
 #elif defined(__linux__)
 #define _LIBCPP_ELAST 4095
 #elif defined(__APPLE__)