diff --git a/src/common.h b/src/common.h
index c062f511e..2b81dfbce 100644
--- a/src/common.h
+++ b/src/common.h
@@ -56,9 +56,6 @@ typedef std::vector<wcstring> wcstring_list_t;
 
 struct termsize_t;
 
-// Maximum number of bytes used by a single utf-8 character.
-#define MAX_UTF8_BYTES 6
-
 // Highest legal ASCII value.
 #define ASCII_MAX 127u
 
@@ -71,9 +68,6 @@ struct termsize_t;
 // Unicode BOM value.
 #define UTF8_BOM_WCHAR 0xFEFFu
 
-// Unicode replacement character.
-#define REPLACEMENT_WCHAR 0xFFFDu
-
 // Use Unicode "noncharacters" for internal characters as much as we can. This
 // gives us 32 "characters" for internal use that we can guarantee should not
 // appear in our input stream. See http://www.unicode.org/faq/private_use.html.
diff --git a/src/env_universal_common.h b/src/env_universal_common.h
index 95182a95b..1fbf2579d 100644
--- a/src/env_universal_common.h
+++ b/src/env_universal_common.h
@@ -215,8 +215,4 @@ class universal_notifier_t {
 
 wcstring get_runtime_path();
 
-// Environment variable for requesting a particular universal notifier. See
-// fetch_default_strategy_from_environment for names.
-#define UNIVERSAL_NOTIFIER_ENV_NAME "fish_universal_notifier"
-
 #endif
diff --git a/src/parse_constants.h b/src/parse_constants.h
index 76451f292..a495f6e35 100644
--- a/src/parse_constants.h
+++ b/src/parse_constants.h
@@ -211,9 +211,6 @@ enum class pipeline_position_t {
     _(L"The function call stack limit has been exceeded. Do you have an accidental infinite " \
       L"loop?")
 
-/// Error message when encountering an illegal command name.
-#define ILLEGAL_CMD_ERR_MSG _(L"Illegal command name '%ls'")
-
 /// Error message when encountering an unknown builtin name.
 #define UNKNOWN_BUILTIN_ERR_MSG _(L"Unknown builtin '%ls'")
 
@@ -226,9 +223,6 @@ enum class pipeline_position_t {
 /// Error message for wildcards with no matches.
 #define WILDCARD_ERR_MSG _(L"No matches for wildcard '%ls'. See `help wildcards-globbing`.")
 
-/// Error message when an expansion produces too many results, e.g. `echo /**`.
-#define EXPAND_OVERFLOW_ERR_MSG _(L"Too many items produced by '%ls'.")
-
 /// Error when using break outside of loop.
 #define INVALID_BREAK_ERR_MSG _(L"'break' while not inside of loop")