diff -Nur xfstt-1.7/src/xfstt.cc xfstt-1.7.new/src/xfstt.cc
--- xfstt-1.7/src/xfstt.cc	2010-05-05 15:26:59.000000000 +0200
+++ xfstt-1.7.new/src/xfstt.cc	2010-05-05 15:44:28.363337556 +0200
@@ -446,11 +446,14 @@
 	char *fontName = nameBase + ttfn->nameOfs;
 
 	TPFontName fn;
-	sprintf(&fn.panose[0][0], "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
+	char tmpbuf[sizeof(fn.panose)+1]; /* includes space for terminating \0 */
+	sprintf(tmpbuf, "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
 		ttfn->bFamilyType, ttfn->bSerifStyle, ttfn->bWeight,
 		ttfn->bProportion, ttfn->bContrast, ttfn->bStrokeVariation,
 		ttfn->bArmStyle, ttfn->bLetterForm, ttfn->bMidLine,
 		ttfn->bXHeight);
+	/* copy only the text, not the terminating \0 */
+	memcpy(&fn.panose[0][0], tmpbuf, sizeof(fn.panose));
 
 	fn.nameLen = sizeof(TPFontName) + ttfn->nameLen;
 	fn.magic[0] = 'T';