diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8010497..542fe0e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -142,10 +142,16 @@ CHECK_INCLUDE_FILE(windows.h    HAVE_WINDOWS_H)
 CHECK_SYMBOL_EXISTS(bcopy         "strings.h"  HAVE_BCOPY)
 CHECK_SYMBOL_EXISTS(memfd_create  "sys/mman.h" HAVE_MEMFD_CREATE)
 CHECK_SYMBOL_EXISTS(memmove       "string.h"   HAVE_MEMMOVE)
-CHECK_SYMBOL_EXISTS(realpath      "stdlib.h"   HAVE_REALPATH)
 CHECK_SYMBOL_EXISTS(secure_getenv "stdlib.h"   HAVE_SECURE_GETENV)
 CHECK_SYMBOL_EXISTS(strerror      "string.h"   HAVE_STRERROR)
 
+CHECK_C_SOURCE_COMPILES(
+  "#include <stdlib.h>
+   #include <limits.h>
+   int main(int c, char *v[]) { char buf[PATH_MAX]; realpath(v[1], buf); return 0; }"
+  HAVE_REALPATH
+)
+
 set(ORIG_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror")
 CHECK_C_SOURCE_COMPILES(
diff --git a/configure.ac b/configure.ac
index 07a0af2..caa4093 100644
--- a/configure.ac
+++ b/configure.ac
@@ -512,7 +512,20 @@ AC_TYPE_SIZE_T
 
 # Checks for library functions.
 
-AC_CHECK_FUNCS(bcopy memfd_create memmove mkostemp realpath secure_getenv strerror)
+AC_CHECK_FUNCS(bcopy memfd_create memmove mkostemp secure_getenv strerror)
+AC_MSG_CHECKING([for realpath])
+AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <stdlib.h>
+#include <limits.h>
+]],[[
+char buffer[PATH_MAX];
+realpath(".", buffer);
+]])],
+[AC_MSG_RESULT([yes])
+ AC_DEFINE([HAVE_REALPATH], 1,
+  [Define to 1 if you have the `realpath' function.])
+],
+AC_MSG_RESULT([no]))
 
 # Check for the availability of libz (aka zlib)