diff --git a/wp-admin/includes/image.php b/wp-admin/includes/image.php
index 4236249fca..fb418c1d45 100644
--- a/wp-admin/includes/image.php
+++ b/wp-admin/includes/image.php
@@ -289,11 +289,16 @@ function wp_read_image_metadata( $file ) {
 			if ( ! empty( $iptc['2#120'][0] ) ) { // description / legacy caption
 				$caption = trim( $iptc['2#120'][0] );
 				if ( empty( $meta['title'] ) ) {
+					mbstring_binary_safe_encoding();
+					$caption_length = strlen( $caption );
+					reset_mbstring_encoding();
+
 					// Assume the title is stored in 2:120 if it's short.
-					if ( mbstring_binary_safe_strlen( $caption ) < 80 )
+					if ( $caption_length < 80 ) {
 						$meta['title'] = $caption;
-					else
+					} else {
 						$meta['caption'] = $caption;
+					}
 				} elseif ( $caption != $meta['title'] ) {
 					$meta['caption'] = $caption;
 				}
@@ -327,7 +332,11 @@ function wp_read_image_metadata( $file ) {
 		}
 
 		if ( ! empty( $exif['ImageDescription'] ) ) {
-			if ( empty( $meta['title'] ) && mbstring_binary_safe_strlen( $exif['ImageDescription'] ) < 80 ) {
+			mbstring_binary_safe_encoding();
+			$description_length = strlen( $exif['ImageDescription'] );
+			reset_mbstring_encoding();
+
+			if ( empty( $meta['title'] ) && $description_length < 80 ) {
 				// Assume the title is stored in ImageDescription
 				$meta['title'] = trim( $exif['ImageDescription'] );
 				if ( empty( $meta['caption'] ) && ! empty( $exif['COMPUTED']['UserComment'] ) && trim( $exif['COMPUTED']['UserComment'] ) != $meta['title'] ) {
diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 3b213931cf..77dee0f505 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -481,7 +481,9 @@ function shortcode_unautop( $pee ) {
  * @return bool True if $str fits a UTF-8 model, false otherwise.
  */
 function seems_utf8($str) {
-	$length = mbstring_binary_safe_strlen($str);
+	mbstring_binary_safe_encoding();
+	$length = strlen($str);
+	reset_mbstring_encoding();
 	for ($i=0; $i < $length; $i++) {
 		$c = ord($str[$i]);
 		if ($c < 0x80) $n = 0; # 0bbbbbbb
@@ -705,7 +707,10 @@ function utf8_uri_encode( $utf8_string, $length = 0 ) {
 	$num_octets = 1;
 	$unicode_length = 0;
 
-	$string_length = mbstring_binary_safe_strlen( $utf8_string );
+	mbstring_binary_safe_encoding();
+	$string_length = strlen( $utf8_string );
+	reset_mbstring_encoding();
+
 	for ($i = 0; $i < $string_length; $i++ ) {
 
 		$value = ord( $utf8_string[ $i ] );
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index a4ad1fe567..33ace4283b 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -4404,24 +4404,6 @@ function reset_mbstring_encoding() {
 	mbstring_binary_safe_encoding( true );
 }
 
-/**
- * Uses a binary-safe encoding to get the length of a string in bytes if func_overload is enabled.
- *
- * @see mbstring_binary_safe_encoding()
- *
- * @since 4.0.0
- *
- * @param string $string The string to get the length of.
- * @return int The length of the string in bytes.
- */
-function mbstring_binary_safe_strlen( $string ) {
-	mbstring_binary_safe_encoding();
-	$length = strlen( $string );
-	reset_mbstring_encoding();
-
-	return $length;
-}
-
 /**
  * Alternative to filter_var( $var, FILTER_VALIDATE_BOOLEAN )
  *