diff --git a/stdlib/public/runtime/EnvironmentVariables.cpp b/stdlib/public/runtime/EnvironmentVariables.cpp
index dfaf099d8a16f..0bcb7d9301abd 100644
--- a/stdlib/public/runtime/EnvironmentVariables.cpp
+++ b/stdlib/public/runtime/EnvironmentVariables.cpp
@@ -118,7 +118,7 @@ void printHelp(const char *extra) {
 // Initialization code.
 OnceToken_t swift::runtime::environment::initializeToken;
 
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__linux__)
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__linux__)
 extern "C" char **environ;
 #define ENVIRON environ
 #elif defined(_WIN32)
diff --git a/test/Runtime/environment_variables.swift b/test/Runtime/environment_variables.swift
index 8f772339d3011..87aa398fe689a 100644
--- a/test/Runtime/environment_variables.swift
+++ b/test/Runtime/environment_variables.swift
@@ -3,7 +3,7 @@
 // RUN: %target-codesign %t/main
 // RUN: env %env-SWIFT_DEBUG_HELP=YES %env-SWIFT_DEBUG_SOME_UNKNOWN_VARIABLE=42 %env-SWIFT_DEBUG_ENABLE_METADATA_ALLOCATION_ITERATION=YES %env-SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT=abc %env-SWIFT_DETERMINISTIC_HASHING=whatever %env-SWIFT_ENABLE_MANGLED_NAME_VERIFICATION=YES %target-run %t/main 2>&1 | %FileCheck %s --dump-input fail
 
-// CHECK-DAG: {{Warning: unknown environment variable SWIFT_DEBUG_SOME_UNKNOWN_VARIABLE|Using getenv to read variables. Unknown variables will not be flagged.}}
+// CHECK-DAG: {{Warning: unknown environment variable SWIFT_DEBUG_SOME_UNKNOWN_VARIABLE|Using getenv to read variables. Unknown SWIFT_DEBUG_ variables will not be flagged.}}
 // CHECK-DAG: Warning: cannot parse value SWIFT_DEBUG_IMPLICIT_OBJC_ENTRYPOINT=abc, defaulting to 2.
 // CHECK-DAG: Warning: cannot parse value SWIFT_DETERMINISTIC_HASHING=whatever, defaulting to false.
 // CHECK-DAG: Swift runtime debugging: