diff --git a/lib/srfi/145.sld b/lib/srfi/145.sld
new file mode 100644
index 00000000..66d1b43b
--- /dev/null
+++ b/lib/srfi/145.sld
@@ -0,0 +1,30 @@
+
+(define-library (srfi 145)
+  (export assume)
+  (import (scheme base))
+  (cond-expand
+   (elide-assumptions
+    (begin
+      (define-syntax assume
+        (syntax-rules ()
+          ((assume expression objs ...)
+           expression)
+          ((assume)
+           (syntax-error "assume requires an expression"))))))
+   (else
+    (begin
+      (define-syntax assume
+        (syntax-rules ()
+          ((assume expression objs ...)
+           (or expression
+               (fatal-error "invalid assumption" 'expression objs ...)))
+          ((assume)
+           (syntax-error "assume requires an expression")))))))
+  (cond-expand
+   (debug
+    (begin
+      (define fatal-error error)))
+   (else
+    (begin
+      (define (fatal-error message . objs)
+        (car 0))))))