diff --git a/refdoc/chapters/data_types.xml b/refdoc/chapters/data_types.xml
index afd325a8d49f78ce75c3a1e39eb13c1531672728..9f1b00d986092d6171a470c85d7d06a7703d4280 100644
--- a/refdoc/chapters/data_types.xml
+++ b/refdoc/chapters/data_types.xml
@@ -709,11 +709,11 @@ section again.</p>
 <dt> compiling</dt>
 <dd> All programs are generated by compiling a string. The string may of
      course be read from a file. For this purpose there are three functions:
-<example>
+<expr>
 program compile(string p);
 program compile_file(string filename);
 program compile_string(string p, string filename);
-</example>
+</expr>
      <tt>compile_file</tt> simply reads the file given as argument, compiles
      it and returns the resulting program. <tt>compile_string</tt> instead
      compiles whatever is in the string <i>p</i>. The second argument,