Index: src/platform/POSIX/OFSubprocess.m
==================================================================
--- src/platform/POSIX/OFSubprocess.m
+++ src/platform/POSIX/OFSubprocess.m
@@ -176,20 +176,21 @@
 					@throw [OFInitializationFailedException
 					    exceptionWithClass: self.class];
 # endif
 
 				if (posix_spawnp(&_pid, path, &actions, &attr,
-				    argv, env) != 0)
+				    argv, (env != NULL ? env : environ)) != 0)
 					@throw [OFInitializationFailedException
 					    exceptionWithClass: self.class];
 			} @finally {
 				posix_spawn_file_actions_destroy(&actions);
 				posix_spawnattr_destroy(&attr);
 			}
 #else
 			if ((_pid = vfork()) == 0) {
-				environ = env;
+				if (env != NULL)
+					environ = env;
 
 				close(_readPipe[0]);
 				close(_writePipe[1]);
 				dup2(_writePipe[0], 0);
 				dup2(_readPipe[1], 1);