diff --git a/configure.ac b/configure.ac
index 99e04e6c1d0..df2c205f197 100644
--- a/configure.ac
+++ b/configure.ac
@@ -643,13 +643,6 @@ if test "$ac_cv_func_getaddrinfo" = yes; then
   AC_DEFINE(HAVE_GETADDRINFO,1,[Define if you have the getaddrinfo function])
 fi
 
-dnl Check for the __sync_fetch_and_add builtin.
-AC_CACHE_CHECK([for __sync_fetch_and_add], ac_cv_func_sync_fetch_and_add,
-[AC_LINK_IFELSE([AC_LANG_PROGRAM([], [[int x;__sync_fetch_and_add(&x,1);]])],[ac_cv_func_sync_fetch_and_add=yes],[ac_cv_func_sync_fetch_and_add=no])])
-if test "$ac_cv_func_sync_fetch_and_add" = yes; then
-  AC_DEFINE(HAVE_SYNC_FETCH_AND_ADD,1,[Define if you have the __sync_fetch_and_add function])
-fi
-
 AC_REPLACE_FUNCS(strlcat strlcpy explicit_bzero getopt)
 AC_FUNC_ALLOCA
 PHP_TIME_R_TYPE
diff --git a/ext/standard/config.m4 b/ext/standard/config.m4
index 171200d18d2..9f82ab1afa1 100644
--- a/ext/standard/config.m4
+++ b/ext/standard/config.m4
@@ -388,11 +388,6 @@ if test "$ac_cv_strptime_decl_fails" = "yes"; then
   AC_DEFINE([HAVE_STRPTIME_DECL_FAILS], 1, [whether strptime() declaration fails])
 fi
 
-dnl
-dnl Check for atomic operation API availability in Solaris
-dnl
-AC_CHECK_HEADERS([atomic.h])
-
 dnl
 dnl Check for arc4random on BSD systems
 dnl
diff --git a/ext/standard/php_crypt_r.c b/ext/standard/php_crypt_r.c
index 96e5905e5ae..432657cf47a 100644
--- a/ext/standard/php_crypt_r.c
+++ b/ext/standard/php_crypt_r.c
@@ -39,11 +39,6 @@
 # include <Wincrypt.h>
 #endif
 
-#ifdef HAVE_ATOMIC_H /* Solaris 10 defines atomic API within */
-# include <atomic.h>
-#else
-# include <signal.h>
-#endif
 #include "php_crypt_r.h"
 #include "crypt_freesec.h"
 
@@ -76,29 +71,17 @@ void php_shutdown_crypt_r()
 
 void _crypt_extended_init_r(void)
 {
-#ifdef PHP_WIN32
-	LONG volatile initialized = 0;
-#elif defined(HAVE_ATOMIC_H) /* Solaris 10 defines atomic API within */
-	volatile unsigned int initialized = 0;
-#else
-	static volatile sig_atomic_t initialized = 0;
-#endif
+	static int initialized = 0;
 
 #ifdef ZTS
 	tsrm_mutex_lock(php_crypt_extended_init_lock);
 #endif
 
 	if (!initialized) {
-#ifdef PHP_WIN32
-		InterlockedIncrement(&initialized);
-#elif defined(HAVE_SYNC_FETCH_AND_ADD)
-		__sync_fetch_and_add(&initialized, 1);
-#elif defined(HAVE_ATOMIC_H) /* Solaris 10 defines atomic API within */
-		membar_producer();
-		atomic_add_int(&initialized, 1);
-#endif
+		initialized = 1;
 		_crypt_extended_init();
 	}
+
 #ifdef ZTS
 	tsrm_mutex_unlock(php_crypt_extended_init_lock);
 #endif