diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0d551a91..42aa0dfa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,8 +5,9 @@ TODO: SRFI 113
 
 Features:
 
-- Thanks to ecraven, added `exact-integer-sqrt`.
+- Thanks to ecraven, added R7RS function `exact-integer-sqrt` to `(scheme base)`.
 - Allow the reader to recognize `+inf.0`, `-inf.0`, `+nan.0`, and `-nan.0`.
+- Allow `cond-expand` to test for whether a library exists using the form `(library {library name})`.
 
 Bug Fixes
 
diff --git a/scheme/base.sld b/scheme/base.sld
index c099750f..2c43f724 100644
--- a/scheme/base.sld
+++ b/scheme/base.sld
@@ -316,48 +316,47 @@
       (er-macro-transformer
         ;; Based on the cond-expand macro from Chibi scheme
         (lambda (expr rename compare)
-;; TODO: port to this macro, so we can use below for library form
-(define (_library-exists? import . ext)
-  (file-exists?
-    (_lib:import->filename 
-      (_lib:import->library-name import)
-      (if (null? ext) ".sld" (car ext)))))
-(define (_lib:import->filename import . ext)
-  (let* ((file-ext 
-          (if (null? ext)
-              ".sld"
-              (car ext)))
-         (filename*
-          (string-append
-            (apply
-              string-append
-              (map 
-                (lambda (i) 
-                  (string-append 
-                    "/" 
-                    (cond
-                      ((symbol? i) (symbol->string i))
-                      ((number? i) (number->string i))
-                      (else (error "Unexpected type in import set")))))
-                import))
-            file-ext))
-         (filename
-           (substring filename* 1 (string-length filename*))))
-    (if (or (equal? 'scheme (car import))
-            (equal? 'srfi   (car import)))
-      (string-append (Cyc-installation-dir 'sld) "/" filename) ;; Built-in library
-      filename)))
-(define (_lib:import->library-name import)
-  (cond
-    ((and (pair? import)
-          (or (equal? 'only   (car import))
-              (equal? 'except (car import))
-              (equal? 'prefix (car import))
-              (equal? 'rename (car import))))
-     (_lib:import->library-name 
-       (cadr import)))
-    (else
-     import)))
+          (define (_library-exists? import . ext)
+            (file-exists?
+              (_lib:import->filename 
+                (_lib:import->library-name import)
+                (if (null? ext) ".sld" (car ext)))))
+          (define (_lib:import->filename import . ext)
+            (let* ((file-ext 
+                    (if (null? ext)
+                        ".sld"
+                        (car ext)))
+                   (filename*
+                    (string-append
+                      (apply
+                        string-append
+                        (map 
+                          (lambda (i) 
+                            (string-append 
+                              "/" 
+                              (cond
+                                ((symbol? i) (symbol->string i))
+                                ((number? i) (number->string i))
+                                (else (error "Unexpected type in import set")))))
+                          import))
+                      file-ext))
+                   (filename
+                     (substring filename* 1 (string-length filename*))))
+              (if (or (equal? 'scheme (car import))
+                      (equal? 'srfi   (car import)))
+                (string-append (Cyc-installation-dir 'sld) "/" filename) ;; Built-in library
+                filename)))
+          (define (_lib:import->library-name import)
+            (cond
+              ((and (pair? import)
+                    (or (equal? 'only   (car import))
+                        (equal? 'except (car import))
+                        (equal? 'prefix (car import))
+                        (equal? 'rename (car import))))
+               (_lib:import->library-name 
+                 (cadr import)))
+              (else
+               import)))
           (define (check x)
             (if (pair? x)
                 (case (car x)