diff --git a/HTMLparser.c b/HTMLparser.c
index 14cc56fa..c9a64c78 100644
--- a/HTMLparser.c
+++ b/HTMLparser.c
@@ -457,7 +457,12 @@ htmlCurrentChar(xmlParserCtxtPtr ctxt, int *len) {
             ctxt->input->encoding = guess;
             handler = xmlFindCharEncodingHandler((const char *) guess);
             if (handler != NULL) {
-                xmlSwitchToEncoding(ctxt, handler);
+                /*
+                 * Don't use UTF-8 encoder which isn't required and
+                 * can produce invalid UTF-8.
+                 */
+                if (!xmlStrEqual(BAD_CAST handler->name, BAD_CAST "UTF-8"))
+                    xmlSwitchToEncoding(ctxt, handler);
             } else {
                 htmlParseErr(ctxt, XML_ERR_INVALID_ENCODING,
                              "Unsupported encoding %s", guess, NULL);
@@ -570,7 +575,16 @@ encoding_error:
 		     BAD_CAST buffer, NULL);
     }
 
-    ctxt->charset = XML_CHAR_ENCODING_8859_1;
+    /*
+     * Don't switch encodings twice. Note that if there's an encoder, we
+     * shouldn't receive invalid UTF-8 anyway.
+     *
+     * Note that if ctxt->input->buf == NULL, switching encodings is
+     * impossible, see Gitlab issue #34.
+     */
+    if ((ctxt->input->buf != NULL) &&
+        (ctxt->input->buf->encoder == NULL))
+        xmlSwitchEncoding(ctxt, XML_CHAR_ENCODING_8859_1);
     *len = 1;
     return((int) *ctxt->input->cur);
 }
diff --git a/encoding.c b/encoding.c
index d67c16d9..cdff6ae7 100644
--- a/encoding.c
+++ b/encoding.c
@@ -373,6 +373,11 @@ UTF8ToUTF8(unsigned char* out, int *outlen,
     if (len < 0)
 	return(-1);
 
+    /*
+     * FIXME: Conversion functions must assure valid UTF-8, so we have
+     * to check for UTF-8 validity. Preferably, this converter shouldn't
+     * be used at all.
+     */
     memcpy(out, inb, len);
 
     *outlen = len;
diff --git a/parserInternals.c b/parserInternals.c
index b0629ef3..cbcfde0e 100644
--- a/parserInternals.c
+++ b/parserInternals.c
@@ -1153,6 +1153,11 @@ xmlSwitchInputEncodingInt(xmlParserCtxtPtr ctxt, xmlParserInputPtr input,
              * Note: this is a bit dangerous, but that's what it
              * takes to use nearly compatible signature for different
              * encodings.
+             *
+             * FIXME: Encoders might buffer partial byte sequences, so
+             * this probably can't work. We should return an error and
+             * make sure that callers never try to switch the encoding
+             * twice.
              */
             xmlCharEncCloseFunc(input->buf->encoder);
             input->buf->encoder = handler;