diff --git a/scheme/interfaces.scm b/scheme/interfaces.scm
index e475f9c..331c826 100644
--- a/scheme/interfaces.scm
+++ b/scheme/interfaces.scm
@@ -154,7 +154,9 @@
 	  output-channel?
 	  open-output-channel
 	  channel-write
-	  close-output-channel))
+	  close-output-channel
+
+	  set-with-fs-context-aligned*!))
 
 (define-interface low-channels-interface
   (export channel?
@@ -172,17 +174,6 @@
 
 	  open-channels-list))
 
-(define-interface channels-interface
-  (export input-channel?
-	  open-input-channel
-	  channel-read	  
-	  close-input-channel
-	  
-	  output-channel?
-	  open-output-channel
-	  channel-write
-	  close-output-channel))
-
 (define-interface ports-interface
   (export port?
 	  make-port
diff --git a/scheme/rts/channel.scm b/scheme/rts/channel.scm
index c123d67..bb00112 100644
--- a/scheme/rts/channel.scm
+++ b/scheme/rts/channel.scm
@@ -16,14 +16,27 @@
 	   (= (channel-status thing)
 	      (enum channel-status-option special-output)))))
 
+;;; Scsh changes umask and cwd lazily
+;;; placeholder until scsh sets it
+(define (with-fs-context-aligned* thunk)
+  (thunk))
+
+(define (set-with-fs-context-aligned*! wpca*)
+  (set! with-fs-context-aligned* wpca*))
+
+
 (define (open-input-channel filename)
-  (let ((channel (open-channel filename (enum channel-status-option input))))
+  (let ((channel (with-fs-context-aligned*
+		  (lambda ()
+		    (open-channel filename (enum channel-status-option input))))))
     (if (channel? channel)
 	channel
 	(error "cannot open input file" filename))))
 
 (define (open-output-channel filename)
-  (let ((channel (open-channel filename (enum channel-status-option output))))
+  (let ((channel (with-fs-context-aligned*
+		  (lambda ()
+		    (open-channel filename (enum channel-status-option output))))))
     (if (channel? channel)
 	channel
 	(error "cannot open output file" filename))))
diff --git a/scsh/scsh.scm b/scsh/scsh.scm
index 7a48e93..8f7e40d 100644
--- a/scsh/scsh.scm
+++ b/scsh/scsh.scm
@@ -247,6 +247,12 @@
 
 (initialize-umask)
 
+(set-with-fs-context-aligned*! ; ensure S48 is aligned too
+ (lambda (thunk)
+   (with-cwd-aligned*
+    (lambda ()
+      (with-umask-aligned*
+       thunk)))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Environment per thread