diff --git a/ext/intl/dateformat/dateformat_create.cpp b/ext/intl/dateformat/dateformat_create.cpp
index 5c96f41fadf35..dbc2273f32970 100644
--- a/ext/intl/dateformat/dateformat_create.cpp
+++ b/ext/intl/dateformat/dateformat_create.cpp
@@ -113,7 +113,8 @@ static zend_result datefmt_ctor(INTERNAL_FUNCTION_PARAMETERS, zend_error_handlin
 	locale = Locale::createFromName(locale_str);
 	/* get*Name accessors being set does not preclude being bogus */
 	if (locale.isBogus() || strlen(locale.getISO3Language()) == 0) {
-		goto error;
+        zend_argument_value_error(1, "\"%s\" is invalid", locale_str);
+		return FAILURE;
 	}
 
 	/* process calendar */
diff --git a/ext/intl/formatter/formatter_main.c b/ext/intl/formatter/formatter_main.c
index ed1806d6bbc55..53c5a3e9be2ab 100644
--- a/ext/intl/formatter/formatter_main.c
+++ b/ext/intl/formatter/formatter_main.c
@@ -17,6 +17,7 @@
 #endif
 
 #include <unicode/ustring.h>
+#include <unicode/uloc.h>
 
 #include "php_intl.h"
 #include "formatter_class.h"
@@ -63,6 +64,11 @@ static int numfmt_ctor(INTERNAL_FUNCTION_PARAMETERS, zend_error_handling *error_
 		locale = intl_locale_get_default();
 	}
 
+	if (strlen(uloc_getISO3Language(locale)) == 0) {
+		zend_argument_value_error(1, "\"%s\" is invalid", locale);
+		return FAILURE;
+	}
+    
 	/* Create an ICU number formatter. */
 	FORMATTER_OBJECT(nfo) = unum_open(style, spattern, spattern_len, locale, NULL, &INTL_DATA_ERROR_CODE(nfo));
 
diff --git a/ext/intl/tests/formatter_fail.phpt b/ext/intl/tests/formatter_fail.phpt
index 2a2908e908c74..c9c621c6b7626 100644
--- a/ext/intl/tests/formatter_fail.phpt
+++ b/ext/intl/tests/formatter_fail.phpt
@@ -119,10 +119,14 @@ Deprecated: numfmt_create(): Passing null to parameter #1 ($locale) of type stri
 
 Deprecated: numfmt_create(): Passing null to parameter #2 ($style) of type int is deprecated in %s on line %d
 
-IntlException: Constructor failed in %s on line %d
-'numfmt_create: number formatter creation failed: U_UNSUPPORTED_ERROR'
-'numfmt_create: number formatter creation failed: U_UNSUPPORTED_ERROR'
-'numfmt_create: number formatter creation failed: U_UNSUPPORTED_ERROR'
+ValueError: NumberFormatter::__construct(): Argument #1 ($locale) "%s" is invalid in %s on line %d
+'U_ZERO_ERROR'
+
+ValueError: NumberFormatter::create(): Argument #1 ($locale) "%s" is invalid in %s on line %d
+'U_ZERO_ERROR'
+
+ValueError: numfmt_create(): Argument #1 ($locale) "%s" is invalid in %s on line %d
+'U_ZERO_ERROR'
 
 TypeError: NumberFormatter::__construct(): Argument #1 ($locale) must be of type string, array given in %s on line %d
 'U_ZERO_ERROR'
diff --git a/ext/intl/tests/gh12282.phpt b/ext/intl/tests/gh12282.phpt
index a30899a08c7d0..b12dc655f7051 100644
--- a/ext/intl/tests/gh12282.phpt
+++ b/ext/intl/tests/gh12282.phpt
@@ -5,18 +5,25 @@ intl
 --FILE--
 <?php
 
-var_dump(new IntlDateFormatter(
-	'xx',
-	IntlDateFormatter::FULL,
-	IntlDateFormatter::FULL,
-	null,
-	null,
-	'w'
-));
-Locale::setDefault('xx');
-var_dump(new IntlDateFormatter(Locale::getDefault()));
---EXPECT--
-object(IntlDateFormatter)#1 (0) {
+try {
+    new IntlDateFormatter(
+	    'xx',
+	    IntlDateFormatter::FULL,
+	    IntlDateFormatter::FULL,
+	    null,
+	    null,
+	    'w'
+    );
+} catch (\ValueError $e) {
+    echo $e->getMessage() . PHP_EOL;
 }
-object(IntlDateFormatter)#1 (0) {
+
+Locale::setDefault('xx');
+try {
+    new IntlDateFormatter(Locale::getDefault());
+} catch (\ValueError $e) {
+    echo $e->getMessage();
 }
+--EXPECT--
+IntlDateFormatter::__construct(): Argument #1 ($locale) "xx" is invalid
+IntlDateFormatter::__construct(): Argument #1 ($locale) "xx" is invalid
diff --git a/ext/intl/tests/gh12727.phpt b/ext/intl/tests/gh12727.phpt
new file mode 100644
index 0000000000000..e04b5eb26a125
--- /dev/null
+++ b/ext/intl/tests/gh12727.phpt
@@ -0,0 +1,15 @@
+--TEST--
+numfmt creation failures
+--EXTENSIONS--
+intl
+--FILE--
+<?php
+
+try {
+    new NumberFormatter('xx', NumberFormatter::DECIMAL);
+} catch (ValueError $e) {
+    echo $e->getMessage();
+}
+?>
+--EXPECTF--
+NumberFormatter::__construct(): Argument #1 ($locale) "%s" is invalid