diff --git a/collects/tests/mzscheme/basic.ss b/collects/tests/mzscheme/basic.ss
index 20addb9c99..20e1fb912f 100644
--- a/collects/tests/mzscheme/basic.ss
+++ b/collects/tests/mzscheme/basic.ss
@@ -1054,13 +1054,22 @@
 (test "my cerveza Mi Mi Mi" regexp-replace r2 "mi cerveza Mi Mi Mi" insert)
 (test "my cerveza My Mi Mi" regexp-replace* r2 "mi cerveza Mi Mi Mi" insert)
 (test "bbb" regexp-replace* "a" "aaa" "b")
+(test '(#"") regexp-match "" (open-input-string "123") 3)
+(test '(#"") regexp-match "$" (open-input-string "123") 3)
+(test '(#"") regexp-match-peek "" (open-input-string "123") 3)
 
 ;; Test weird port offsets:
 (define (test-weird-offset regexp-match regexp-match-positions)
   (test #f regexp-match "e" (open-input-string ""))
   (test #f regexp-match "e" (open-input-string "") (expt 2 100))
   (test #f regexp-match "e" (open-input-string "") (expt 2 100) (expt 2 101))
-  (test '((3 . 4)) regexp-match-positions "e" (open-input-string "eaae") 2 (expt 2 101)))
+  (test #f regexp-match "e" (open-input-string "") (expt 2 100) (expt 2 101))
+  (test '((3 . 4)) regexp-match-positions "e" (open-input-string "eaae") 2 (expt 2 101))
+  (test #f regexp-match "" (open-input-string "123") 4)
+  (test #f regexp-match-positions "" (open-input-string "123") 4)
+  (test #f regexp-match "" (open-input-string "123") 999)
+  (test #f regexp-match-positions "" (open-input-string "123") 999)
+  (test #f regexp-match "" (open-input-string "123") (expt 2 101)))
 (test-weird-offset regexp-match regexp-match-positions)
 (test-weird-offset regexp-match-peek regexp-match-peek-positions)
 
diff --git a/collects/tests/mzscheme/module.ss b/collects/tests/mzscheme/module.ss
index d50b6e4cfa..9ad1f95ba0 100644
--- a/collects/tests/mzscheme/module.ss
+++ b/collects/tests/mzscheme/module.ss
@@ -184,9 +184,12 @@
     (eval `(require 'f))
     (let ([finished '(f b e  a d c b  d c b d c b c)])
       (test finished values l)
-      (let ([n2 (make-empty-namespace)])
+      (namespace-attach-module n ''f)
+      (test finished values l)
+      (parameterize ([current-namespace (make-empty-namespace)])
 	(namespace-attach-module n ''f)
 	(test finished values l)
+        (namespace-require 'scheme/base)
 	(eval `(require 'a))
 	(eval `(require 'f))
 	(test finished values l)))))
diff --git a/collects/tests/r6rs/io/simple.ss b/collects/tests/r6rs/io/simple.ss
index ec8f006073..3e4d193337 100644
--- a/collects/tests/r6rs/io/simple.ss
+++ b/collects/tests/r6rs/io/simple.ss
@@ -77,6 +77,10 @@
                      (test (read) (eof-object))
                      (values 70 80 90)))
                  70 80 90)
+
+    (test/unspec
+     (when (file-exists? "io-tmp2")
+       (delete-file "io-tmp2")))
     
     (test (input-port? (current-input-port)) #t)
     (test (binary-port? (current-input-port)) #f)
diff --git a/src/mzscheme/src/regexp.c b/src/mzscheme/src/regexp.c
index 2177213cb2..1d56d9c338 100644
--- a/src/mzscheme/src/regexp.c
+++ b/src/mzscheme/src/regexp.c
@@ -2434,6 +2434,19 @@ regexec(const char *who,
     if (peek) {
       peekskip = portstart;
       dropped = portstart;
+      /* Make sure that's there's not an EOF before peekskip: */
+      if (!SAME_OBJ(peekskip, scheme_make_integer(0))) {
+        char tmp[1];
+        long got;
+        got = scheme_get_byte_string_unless("regexp-match", port, 
+                                            tmp, 0, 1, 1,
+                                            1, scheme_bin_minus(peekskip, scheme_make_integer(1)),
+                                            unless_evt);
+        if (got == EOF) {
+          /* Hit EOF before peekstart, so cannot match */
+          return 0;
+        }
+      }
     } else {
       /* In non-peek port mode, skip over portstart chars: */
       long amt, got;
@@ -2460,7 +2473,7 @@ regexec(const char *who,
 	    if (discard_oport)
 	      scheme_put_byte_string(who, discard_oport, drain, 0, got, 0);
 	    
-	    dropped = scheme_bin_plus(dropped, scheme_make_integer(amt));
+	    dropped = scheme_bin_plus(dropped, scheme_make_integer(got));
 	    delta = scheme_bin_minus(portstart, dropped);
 	    if (scheme_bin_gt(scheme_make_integer(amt), delta))
 	      amt = SCHEME_INT_VAL(delta);