diff --git a/parso/python/fstring.py b/parso/python/fstring.py
index 025a48c..50ee09c 100644
--- a/parso/python/fstring.py
+++ b/parso/python/fstring.py
@@ -144,11 +144,11 @@ def _tokenize(code, start_pos=(1, 0)):
                         search *= 3
                         start += 2
 
-                    index = code.find(search)
+                    index = code.find(search, start)
                     if index == -1:
                         index = len(code)
                     expression += code[start:index]
-                    start = index
+                    start = index + 1
                 elif found == '!' and len(code) > start and code[start] == '=':
                     # This is a python `!=` and not a conversion.
                     expression += found
diff --git a/test/failing_examples.py b/test/failing_examples.py
index 7127ac3..89dc359 100644
--- a/test/failing_examples.py
+++ b/test/failing_examples.py
@@ -142,7 +142,7 @@ FAILING_EXAMPLES = [
     # f-strings
     'f"{}"',
     'f"{\\}"',
-    #'f"{\'\\\'}"',
+    'f"{\'\\\'}"',
     'f"{#}"',
 ]