diff --git a/ansi-tests/mismatch.lsp b/ansi-tests/mismatch.lsp
index 1b52e60612462b554674f43a2cc3ef96d51fd1f2..bcfaf3012d47400dd48d0385662e3e1b1fa735b8 100644
--- a/ansi-tests/mismatch.lsp
+++ b/ansi-tests/mismatch.lsp
@@ -597,6 +597,21 @@
      (mismatch m a :from-end t)))
   (4 4 5 nil nil 6 5 6))
 
+(deftest mistmatch-string.25
+  (let ((s0 "12345")
+	(s1 "123A")
+	(s2 "245"))
+    (do-special-strings
+     (s s0 nil)
+     (assert (null (mismatch s s0)))
+     (assert (null (mismatch s0 s)))
+     (assert (null (mismatch s s0 :from-end t)))
+     (assert (null (mismatch s0 s :from-end t)))
+     (assert (eql (mismatch s s1) 3))
+     (assert (eql (mismatch s1 s) 3))
+     ))
+  nil)
+
 ;;; test and test-not tests
 
 (defharmless mismatch.test-and-test-not.1
diff --git a/ansi-tests/search-string.lsp b/ansi-tests/search-string.lsp
index 791d919ffb11eb9eb3547c42479f91517fea68d0..a0fcfda63c9266258355cc05863236cc9f4179fc 100644
--- a/ansi-tests/search-string.lsp
+++ b/ansi-tests/search-string.lsp
@@ -175,4 +175,23 @@
   (let ((pat "m")
 	(target '"adgmnpq"))
     (search pat target :test-not #'char>=))
-  4)
\ No newline at end of file
+  4)
+
+;;; Specialized strings
+
+(deftest search-string.19
+  (do-special-strings
+   (s "a" nil)
+   (assert (eql (search s "xyza123apqr") 3))
+   (assert (eql (search s "xyza1a3apqr" :start2 4) 5))
+   (assert (eql (search s "xyza123apqr" :from-end t) 7)))
+  nil)
+
+(deftest search-string.20
+  (do-special-strings
+   (s "xababcdefabc123ababc18" nil)
+   (assert (eql (search "abc" s) 3))
+   (assert (eql (search "abc" s :start2 4) 9))
+   (assert (eql (search "abc" s :from-end t) 17)))
+  nil)
+