diff --git a/ext/intl/locale/locale_methods.c b/ext/intl/locale/locale_methods.c
index 50838de7ed8fa..1c4ba327bd83c 100644
--- a/ext/intl/locale/locale_methods.c
+++ b/ext/intl/locale/locale_methods.c
@@ -149,7 +149,7 @@ static zend_off_t getStrrtokenPos(char* str, zend_off_t savedPos)
 	zend_off_t i;
 
 	for(i=savedPos-1; i>=0; i--) {
-		if(isIDSeparator(*(str+i)) ){
+		if(isIDSeparator(*(str+i)) || isKeywordSeparator(*(str+i))){
 			/* delimiter found; check for singleton */
 			if(i>=2 && isIDSeparator(*(str+i-2)) ){
 				/* a singleton; so send the position of token before the singleton */
diff --git a/ext/intl/tests/locale/bug72809.phpt b/ext/intl/tests/locale/bug72809.phpt
new file mode 100644
index 0000000000000..98dc7d39694da
--- /dev/null
+++ b/ext/intl/tests/locale/bug72809.phpt
@@ -0,0 +1,18 @@
+--TEST--
+Bug #72809 (Locale::lookup() wrong result with canonicalize option)
+--SKIPIF--
+<?php
+if (!extension_loaded('intl')) die("skip intl extension not avaible");
+?>
+--FILE--
+<?php
+var_dump(
+    Locale::lookup(['en', 'en-US'], 'en-US-u-cu-EUR-tz-deber-fw-mon', true),
+    Locale::lookup(['en', 'en_US'], 'en_US@currency=eur;fw=mon;timezone=Europe/Berlin', false),
+    Locale::lookup(['en', 'en_US'], 'en_US@currency=eur;fw=mon;timezone=Europe/Berlin', true),
+);
+?>
+--EXPECT--
+string(5) "en_us"
+string(5) "en_US"
+string(5) "en_us"