diff --git a/Zend/zend_config.w32.h b/Zend/zend_config.w32.h
index 47cdf6af8ce81..a44a8b9f70d24 100644
--- a/Zend/zend_config.w32.h
+++ b/Zend/zend_config.w32.h
@@ -36,6 +36,7 @@
 #include <winsock2.h>
 #include <windows.h>
 
+#include <intsafe.h>
 #include <float.h>
 
 #define strcasecmp(s1, s2) _stricmp(s1, s2)
diff --git a/Zend/zend_operators.h b/Zend/zend_operators.h
index f8c901b149806..7ed441965ed5c 100644
--- a/Zend/zend_operators.h
+++ b/Zend/zend_operators.h
@@ -579,6 +579,22 @@ overflow: ZEND_ATTRIBUTE_COLD_LABEL
 	} else {
 		Z_LVAL_P(op1) = llresult;
 	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG == SIZEOF_ZEND_LONG
+	long lresult;
+	if (UNEXPECTED(FAILED(LongAdd(Z_LVAL_P(op1), 1, &lresult)))) {
+		/* switch to double */
+		ZVAL_DOUBLE(op1, (double)ZEND_LONG_MAX + 1.0);
+	} else {
+		Z_LVAL_P(op1) = lresult;
+	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG_LONG == SIZEOF_ZEND_LONG
+	long long llresult;
+	if (UNEXPECTED(FAILED(LongLongAdd(Z_LVAL_P(op1), 1, &llresult)))) {
+		/* switch to double */
+		ZVAL_DOUBLE(op1, (double)ZEND_LONG_MAX + 1.0);
+	} else {
+		Z_LVAL_P(op1) = llresult;
+	}
 #else
 	if (UNEXPECTED(Z_LVAL_P(op1) == ZEND_LONG_MAX)) {
 		/* switch to double */
@@ -642,6 +658,22 @@ overflow: ZEND_ATTRIBUTE_COLD_LABEL
 	} else {
 		Z_LVAL_P(op1) = llresult;
 	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG == SIZEOF_ZEND_LONG
+	long lresult;
+	if (UNEXPECTED(FAILED(LongSub(Z_LVAL_P(op1), 1, &lresult)))) {
+		/* switch to double */
+		ZVAL_DOUBLE(op1, (double)ZEND_LONG_MIN - 1.0);
+	} else {
+		Z_LVAL_P(op1) = lresult;
+	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG_LONG == SIZEOF_ZEND_LONG
+	long long llresult;
+	if (UNEXPECTED(FAILED(LongLongSub(Z_LVAL_P(op1), 1, &llresult)))) {
+		/* switch to double */
+		ZVAL_DOUBLE(op1, (double)ZEND_LONG_MIN - 1.0);
+	} else {
+		Z_LVAL_P(op1) = llresult;
+	}
 #else
 	if (UNEXPECTED(Z_LVAL_P(op1) == ZEND_LONG_MIN)) {
 		/* switch to double */
@@ -724,6 +756,20 @@ overflow: ZEND_ATTRIBUTE_COLD_LABEL
 	} else {
 		ZVAL_LONG(result, llresult);
 	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG == SIZEOF_ZEND_LONG
+	long lresult;
+	if (UNEXPECTED(FAILED(LongAdd(Z_LVAL_P(op1), Z_LVAL_P(op2), &lresult)))) {
+		ZVAL_DOUBLE(result, (double) Z_LVAL_P(op1) + (double) Z_LVAL_P(op2));
+	} else {
+		ZVAL_LONG(result, lresult);
+	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG_LONG == SIZEOF_ZEND_LONG
+	long long llresult;
+	if (UNEXPECTED(FAILED(LongLongAdd(Z_LVAL_P(op1), Z_LVAL_P(op2), &llresult)))) {
+		ZVAL_DOUBLE(result, (double) Z_LVAL_P(op1) + (double) Z_LVAL_P(op2));
+	} else {
+		ZVAL_LONG(result, llresult);
+	}
 #else
 	/*
 	 * 'result' may alias with op1 or op2, so we need to
@@ -812,6 +858,20 @@ overflow: ZEND_ATTRIBUTE_COLD_LABEL
 	} else {
 		ZVAL_LONG(result, llresult);
 	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG == SIZEOF_ZEND_LONG
+	long lresult;
+	if (UNEXPECTED(FAILED(LongSub(Z_LVAL_P(op1), Z_LVAL_P(op2), &lresult)))) {
+		ZVAL_DOUBLE(result, (double) Z_LVAL_P(op1) - (double) Z_LVAL_P(op2));
+	} else {
+		ZVAL_LONG(result, lresult);
+	}
+#elif defined(ZEND_WIN32) && SIZEOF_LONG_LONG == SIZEOF_ZEND_LONG
+	long long llresult;
+	if (UNEXPECTED(FAILED(LongLongSub(Z_LVAL_P(op1), Z_LVAL_P(op2), &llresult)))) {
+		ZVAL_DOUBLE(result, (double) Z_LVAL_P(op1) - (double) Z_LVAL_P(op2));
+	} else {
+		ZVAL_LONG(result, llresult);
+	}
 #else
 	ZVAL_LONG(result, Z_LVAL_P(op1) - Z_LVAL_P(op2));
 
diff --git a/ext/pdo_firebird/php_pdo_firebird_int.h b/ext/pdo_firebird/php_pdo_firebird_int.h
index db7b730ead40d..a62c152ffab3e 100644
--- a/ext/pdo_firebird/php_pdo_firebird_int.h
+++ b/ext/pdo_firebird/php_pdo_firebird_int.h
@@ -33,8 +33,6 @@
 #define PDO_FB_DEF_TIME_FMT "%H:%M:%S"
 #define PDO_FB_DEF_TIMESTAMP_FMT PDO_FB_DEF_DATE_FMT " " PDO_FB_DEF_TIME_FMT
 
-#define SHORT_MAX (1 << (8*sizeof(short)-1))
-
 #if SIZEOF_ZEND_LONG == 8 && !defined(PHP_WIN32)
 # define LL_LIT(lit) lit ## L
 #else
diff --git a/win32/build/config.w32 b/win32/build/config.w32
index 70e50891964b0..d2f8a611180e3 100644
--- a/win32/build/config.w32
+++ b/win32/build/config.w32
@@ -370,6 +370,10 @@ if (VS_TOOLSET) {
 		}
 	}
 } else if (CLANG_TOOLSET) {
+	AC_DEFINE("PHP_HAVE_BUILTIN_SADDL_OVERFLOW", 1, "Define to 1 if the compiler supports '__builtin_saddl_overflow'.");
+	AC_DEFINE("PHP_HAVE_BUILTIN_SADDLL_OVERFLOW", 1, "Define to 1 if the compiler supports '__builtin_saddll_overflow'.");
+	AC_DEFINE("PHP_HAVE_BUILTIN_SSUBL_OVERFLOW", 1, "Define to 1 if the compiler supports '__builtin_ssubl_overflow'.");
+	AC_DEFINE("PHP_HAVE_BUILTIN_SSUBLL_OVERFLOW", 1, "Define to 1 if the compiler supports '__builtin_ssubll_overflow'.");
 	if (PHP_UNCRITICAL_WARN_CHOKE != "no") {
 		ADD_FLAG("CFLAGS", "-Wno-ignored-attributes -Wno-deprecated-declarations -Wno-missing-braces " +
 		"-Wno-logical-op-parentheses -Wno-msvc-include -Wno-invalid-source-encoding -Wno-unknown-pragmas " +
diff --git a/win32/build/confutils.js b/win32/build/confutils.js
index 032e534bb0d19..314fd1f84508d 100644
--- a/win32/build/confutils.js
+++ b/win32/build/confutils.js
@@ -3318,6 +3318,11 @@ function toolset_setup_common_cflags()
 		var vc_ver = probe_binary(PATH_PROG('cl', null));
 		ADD_FLAG("CFLAGS"," -fms-compatibility -fms-compatibility-version=" + vc_ver + " -fms-extensions");
 	}
+
+	if (!CLANG_TOOLSET) {
+		/* clang uses __builtin_*() instead */
+		ADD_FLAG("CFLAGS", "/DENABLE_INTSAFE_SIGNED_FUNCTIONS");
+	}
 }
 
 function toolset_setup_intrinsic_cflags()