diff --git a/doc/site/core-library.markdown b/doc/site/core-library.markdown
index f37c67a6..8cbcbc9d 100644
--- a/doc/site/core-library.markdown
+++ b/doc/site/core-library.markdown
@@ -244,7 +244,7 @@ It is a runtime error if `other` is not a number.
 
 ## String Class
 
-An object representing a string that is created via the string literal syntax.
+A string of Unicode code points stored in UTF-8.
 
 ### **contains**(other)
 
@@ -264,8 +264,8 @@ It is a runtime error if `suffix` is not a string.
 
 ### **indexOf(search)**
 
-Returns the index of `search` in the string or -1 if `search` is not a substring
-of the string.
+Returns the index of `search` in the string or -1 if `search` is not a
+substring of the string.
 
 It is a runtime error if `search` is not a string.
 
@@ -291,11 +291,12 @@ Check if the string is not equal to `other`.
 
 ### **[**index**]** operator
 
-Returns a one character string of the value at `index`. This does not handle
-UTF-8 characters correctly.
+Returns a one character string of the value at `index`.
 
 It is a runtime error if `index` is greater than the length of the string.
 
+*Note: This does not currently handle UTF-8 characters correctly.*
+
 ## List Class
 
 **TODO**
diff --git a/src/wren_core.c b/src/wren_core.c
index ccd80b45..0ee7f528 100644
--- a/src/wren_core.c
+++ b/src/wren_core.c
@@ -955,7 +955,7 @@ DEF_NATIVE(string_indexOf)
 
   char* firstOccurrence = strstr(string->value, search->value);
 
-  RETURN_NUM(firstOccurrence ? (firstOccurrence - string->value) : -1);
+  RETURN_NUM(firstOccurrence ? firstOccurrence - string->value : -1);
 }
 
 DEF_NATIVE(string_startsWith)
diff --git a/test/string/indexOf.wren b/test/string/index_of.wren
similarity index 75%
rename from test/string/indexOf.wren
rename to test/string/index_of.wren
index 67106d5c..7f983f58 100644
--- a/test/string/indexOf.wren
+++ b/test/string/index_of.wren
@@ -1,4 +1,4 @@
 IO.print("abcd".indexOf("cd")) // expect: 2
 IO.print("abcd".indexOf("a")) // expect: 0
 IO.print("abcd".indexOf("abcde")) // expect: -1
-IO.print("abab".indexOf("ab")) // expect: 0
\ No newline at end of file
+IO.print("abab".indexOf("ab")) // expect: 0
diff --git a/test/string/indexOf_invalid_arg.wren b/test/string/index_of_invalid_arg.wren
similarity index 77%
rename from test/string/indexOf_invalid_arg.wren
rename to test/string/index_of_invalid_arg.wren
index 171c0bd0..5d9393c5 100644
--- a/test/string/indexOf_invalid_arg.wren
+++ b/test/string/index_of_invalid_arg.wren
@@ -1 +1 @@
-IO.print("abcd".indexOf(null)) // expect runtime error: Argument must be a string.
\ No newline at end of file
+IO.print("abcd".indexOf(null)) // expect runtime error: Argument must be a string.
diff --git a/test/string/startsWith.wren b/test/string/starts_with.wren
similarity index 81%
rename from test/string/startsWith.wren
rename to test/string/starts_with.wren
index be9691c0..cc2879e8 100644
--- a/test/string/startsWith.wren
+++ b/test/string/starts_with.wren
@@ -2,4 +2,4 @@ IO.print("abcd".startsWith("cd")) // expect: false
 IO.print("abcd".startsWith("a")) // expect: true
 IO.print("abcd".startsWith("abcd")) // expect: true
 IO.print("abcd".startsWith("abcde")) // expect: false
-IO.print("abcd".startsWith("")) // expect: true
\ No newline at end of file
+IO.print("abcd".startsWith("")) // expect: true
diff --git a/test/string/startsWith_invalid_arg.wren b/test/string/starts_with_invalid_arg.wren
similarity index 74%
rename from test/string/startsWith_invalid_arg.wren
rename to test/string/starts_with_invalid_arg.wren
index 25ffc605..7863aebc 100644
--- a/test/string/startsWith_invalid_arg.wren
+++ b/test/string/starts_with_invalid_arg.wren
@@ -1 +1 @@
-IO.print("abcd".startsWith(null)) // expect runtime error: Argument must be a string.
\ No newline at end of file
+IO.print("abcd".startsWith(null)) // expect runtime error: Argument must be a string.