diff --git a/src/main/scala/li/cil/oc/util/TextBuffer.scala b/src/main/scala/li/cil/oc/util/TextBuffer.scala
index 23dd12841..1d885a8eb 100644
--- a/src/main/scala/li/cil/oc/util/TextBuffer.scala
+++ b/src/main/scala/li/cil/oc/util/TextBuffer.scala
@@ -128,7 +128,7 @@ class TextBuffer(var width: Int, var height: Int, initialFormat: PackedColor.Col
           val c = s(x - col)
           changed = changed || (line(bx) != c) || (lineColor(bx) != packed)
           setChar(line, lineColor, bx, c)
-          bx += FontUtil.wcwidth(c)
+          bx += math.max(1, FontUtil.wcwidth(c))
         }
         changed
       }
@@ -147,7 +147,7 @@ class TextBuffer(var width: Int, var height: Int, initialFormat: PackedColor.Col
       for (x <- bx until math.min(col + w, width) if bx < line.length) {
         changed = changed || (line(bx) != c) || (lineColor(bx) != packed)
         setChar(line, lineColor, bx, c)
-        bx += FontUtil.wcwidth(c)
+        bx += math.max(1, FontUtil.wcwidth(c))
       }
     }
     changed