diff --git a/wsutil/unicode-utils.c b/wsutil/unicode-utils.c
index 2ade075ad9..764c0b3c03 100644
--- a/wsutil/unicode-utils.c
+++ b/wsutil/unicode-utils.c
@@ -12,18 +12,24 @@
 
 #include "unicode-utils.h"
 
-int
-ws_utf8_char_len(guint8 ch)
-{
-  if (ch >= 0xfe) return -1;
-  if (ch >= 0xfc) return  6;
-  if (ch >= 0xf8) return  5;
-  if (ch >= 0xf0) return  4;
-  if (ch >= 0xe0) return  3;
-  if (ch >= 0xc0) return  2;
-  else            return  1;
-}
-
+int ws_utf8_seqlen[256] = {
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x00...0x0f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x10...0x1f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x20...0x2f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x30...0x3f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x40...0x4f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x50...0x5f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x60...0x6f */
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  /* 0x70...0x7f */
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  /* 0x80...0x8f */
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  /* 0x90...0x9f */
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  /* 0xa0...0xaf */
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  /* 0xb0...0xbf */
+  0,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2,  /* 0xc0...0xcf */
+  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,  /* 0xd0...0xdf */
+  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,  /* 0xe0...0xef */
+  4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,  /* 0xf0...0xff */
+};
 
 #ifdef _WIN32
 
diff --git a/wsutil/unicode-utils.h b/wsutil/unicode-utils.h
index 2ffb90ad32..538d2b03de 100644
--- a/wsutil/unicode-utils.h
+++ b/wsutil/unicode-utils.h
@@ -59,8 +59,16 @@ extern "C" {
   } while (0)
 
 
-WS_DLL_PUBLIC
-int ws_utf8_char_len(guint8 ch);
+WSUTIL_EXPORT
+int ws_utf8_seqlen[256];
+
+/** Given the first byte in an UTF-8 encoded code point,
+ * return the length of the multibyte sequence, or *ZERO*
+ * if the byte is invalid as the first byte in a multibyte
+ * sequence.
+ */
+#define ws_utf8_char_len(ch)  (ws_utf8_seqlen[(ch)])
+
 
 #ifdef _WIN32