diff --git a/src/safeguards.h b/src/safeguards.h
index 02da05b918..09cfe9a919 100644
--- a/src/safeguards.h
+++ b/src/safeguards.h
@@ -40,7 +40,7 @@
 #define strcat    SAFEGUARD_DO_NOT_USE_THIS_METHOD
 #define strncat   SAFEGUARD_DO_NOT_USE_THIS_METHOD
 
-/* Use seprintf instead. */
+/* Use fmt::format instead. */
 #define sprintf   SAFEGUARD_DO_NOT_USE_THIS_METHOD
 #define snprintf  SAFEGUARD_DO_NOT_USE_THIS_METHOD
 
diff --git a/src/stdafx.h b/src/stdafx.h
index 4056af22a7..ea90c310b0 100644
--- a/src/stdafx.h
+++ b/src/stdafx.h
@@ -90,10 +90,6 @@
 #if defined(__GNUC__) || (defined(__clang__) && !defined(_MSC_VER))
 #	define NORETURN __attribute__ ((noreturn))
 #	define CDECL
-#	define __int64 long long
-	/* Warn about functions using 'printf' format syntax. First argument determines which parameter
-	 * is the format string, second argument is start of values passed to printf. */
-#	define WARN_FORMAT(string, args) __attribute__ ((format (printf, string, args)))
 #	if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7)
 #		define FINAL final
 #	else
@@ -128,7 +124,6 @@
 #if defined(__WATCOMC__)
 #	define NORETURN
 #	define CDECL
-#	define WARN_FORMAT(string, args)
 #	define FINAL
 #	define FALLTHROUGH
 #	include <malloc.h>
@@ -170,7 +165,6 @@
 #	endif
 
 #	define CDECL _cdecl
-#	define WARN_FORMAT(string, args)
 #	define FINAL final
 
 	/* fallthrough attribute, VS 2017 */
diff --git a/src/string.cpp b/src/string.cpp
index 800efecb22..4795a226e7 100644
--- a/src/string.cpp
+++ b/src/string.cpp
@@ -21,7 +21,6 @@
 #include <iomanip>
 
 #ifdef _MSC_VER
-#	include <errno.h> // required by vsnprintf implementation for MSVC
 #	define strncasecmp strnicmp
 #endif
 
@@ -44,10 +43,7 @@
 #	include "os/macosx/string_osx.h"
 #endif
 
-/* The function vsnprintf is used internally to perform the required formatting
- * tasks. As such this one must be allowed, and makes sure it's terminated. */
 #include "safeguards.h"
-#undef vsnprintf
 
 
 /**
@@ -455,67 +451,6 @@ bool IsValidChar(WChar key, CharSetFilter afilter)
 	}
 }
 
-#ifdef _WIN32
-#if defined(_MSC_VER) && _MSC_VER < 1900
-/**
- * Almost POSIX compliant implementation of \c vsnprintf for VC compiler.
- * The difference is in the value returned on output truncation. This
- * implementation returns size whereas a POSIX implementation returns
- * size or more (the number of bytes that would be written to str
- * had size been sufficiently large excluding the terminating null byte).
- */
-int CDECL vsnprintf(char *str, size_t size, const char *format, va_list ap)
-{
-	if (size == 0) return 0;
-
-	errno = 0;
-	int ret = _vsnprintf(str, size, format, ap);
-
-	if (ret < 0) {
-		if (errno != ERANGE) {
-			/* There's a formatting error, better get that looked
-			 * at properly instead of ignoring it. */
-			NOT_REACHED();
-		}
-	} else if ((size_t)ret < size) {
-		/* The buffer is big enough for the number of
-		 * characters stored (excluding null), i.e.
-		 * the string has been null-terminated. */
-		return ret;
-	}
-
-	/* The buffer is too small for _vsnprintf to write the
-	 * null-terminator at its end and return size. */
-	str[size - 1] = '\0';
-	return (int)size;
-}
-#endif /* _MSC_VER */
-
-#endif /* _WIN32 */
-
-/**
- * Safer implementation of snprintf; same as snprintf except:
- * - last instead of size, i.e. replace sizeof with lastof.
- * - return gives the amount of characters added, not what it would add.
- * @param str    buffer to write to up to last
- * @param last   last character we may write to
- * @param format the formatting (see snprintf)
- * @return the number of added characters
- */
-int CDECL seprintf(char *str, const char *last, const char *format, ...)
-{
-	ptrdiff_t diff = last - str;
-	if (diff < 0) return 0;
-
-	va_list ap;
-
-	va_start(ap, format);
-	int ret = std::min(static_cast<int>(diff), vsnprintf(str, diff + 1, format, ap));
-
-	va_end(ap);
-	return ret;
-}
-
 
 /* UTF-8 handling routines */
 
diff --git a/src/string_func.h b/src/string_func.h
index 517ced814d..62f472d26f 100644
--- a/src/string_func.h
+++ b/src/string_func.h
@@ -7,18 +7,6 @@
 
 /**
  * @file string_func.h Functions related to low-level strings.
- *
- * @note Be aware of "dangerous" string functions; string functions that
- * have behaviour that could easily cause buffer overruns and such:
- * - strncpy: does not '\0' terminate when input string is longer than
- *   the size of the output string. Use strecpy instead.
- * - [v]snprintf: returns the length of the string as it would be written
- *   when the output is large enough, so it can be more than the size of
- *   the buffer and than can underflow size_t (uint-ish) which makes all
- *   subsequent snprintf alikes write outside of the buffer. Use
- *   [v]seprintf instead; it will return the number of bytes actually
- *   added so no [v]seprintf will cause outside of bounds writes.
- * - [v]sprintf: does not bounds checking: use [v]seprintf instead.
  */
 
 #ifndef STRING_FUNC_H
@@ -33,8 +21,6 @@
 char *strecpy(char *dst, const char *src, const char *last) NOACCESS(3);
 char *stredup(const char *src, const char *last = nullptr) NOACCESS(2);
 
-int CDECL seprintf(char *str, const char *last, const char *format, ...) WARN_FORMAT(3, 4) NOACCESS(2);
-
 std::string FormatArrayAsHex(span<const byte> data);
 
 void StrMakeValidInPlace(char *str, const char *last, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK) NOACCESS(2);