diff --git a/ext/mbstring/libmbfl/mbfl/mbfilter.c b/ext/mbstring/libmbfl/mbfl/mbfilter.c
index 01797cc01aa..69704489fd0 100644
--- a/ext/mbstring/libmbfl/mbfl/mbfilter.c
+++ b/ext/mbstring/libmbfl/mbfl/mbfilter.c
@@ -362,11 +362,9 @@ int mbfl_encoding_detector_feed(mbfl_encoding_detector *identd, mbfl_string *str
 		p++;
 	}
 
-	if (identd->strict) {
-		for (int i = 0; i < num; i++) {
-			mbfl_convert_filter *filter = identd->filter_list[i];
-			(filter->filter_flush)(filter);
-		}
+	for (int i = 0; i < num; i++) {
+		mbfl_convert_filter *filter = identd->filter_list[i];
+		(filter->filter_flush)(filter);
 	}
 
 	return 0;
diff --git a/ext/mbstring/tests/mb_detect_encoding_incomplete_sequence.phpt b/ext/mbstring/tests/mb_detect_encoding_incomplete_sequence.phpt
new file mode 100644
index 00000000000..3eccb789a88
--- /dev/null
+++ b/ext/mbstring/tests/mb_detect_encoding_incomplete_sequence.phpt
@@ -0,0 +1,15 @@
+--TEST--
+mb_detect_encoding() with incomplete trailing sequence
+--EXTENSIONS--
+mbstring
+--FILE--
+<?php
+
+// Even in non-strict mode, this should detect as ISO-8859-1. When the end of the string is
+// reached neither have illegal characters and would be picked based on score. However, flushing
+// the string will disqualify UTF-8 due to illegal characters.
+var_dump(mb_detect_encoding("A\xC2", ["UTF-8", "ISO-8859-1"]));
+
+?>
+--EXPECT--
+string(10) "ISO-8859-1"