diff --git a/Sources/Soto/Extensions/STS/Environment.swift b/Sources/Soto/Extensions/STS/Environment.swift
index 59ec727ce5..7c9ae01322 100644
--- a/Sources/Soto/Extensions/STS/Environment.swift
+++ b/Sources/Soto/Extensions/STS/Environment.swift
@@ -12,10 +12,14 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if os(Linux)
+#if canImport(Glibc)
 import Glibc
-#else
+#elseif canImport(Musl)
+import Musl
+#elseif canImport(Darwin)
 import Darwin.C
+#else
+#error("The Soto module was unable to identify your C library.")
 #endif
 
 enum Environment {