--- rxvt-unicode/configure	2009/09/04 15:40:12	1.129
+++ rxvt-unicode/configure	2009/12/26 10:24:04	1.130
@@ -1296,6 +1296,7 @@
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --enable-everything     enable standard non-multichoice features
                           NOTE: this option is order dependent
+  --enable-assert         enable assertions
   --enable-warnings       turn on g++ warnings
   --enable-unicode3       use 21 instead of 16 bits to represent unicode characters
   --enable-combining      enable composition of base and combining characters
@@ -4455,6 +4456,22 @@
 fi
 
 
+ASSERTIONS=no
+# Check whether --enable-assert was given.
+if test "${enable_assert+set}" = set; then
+  enableval=$enable_assert; if test x$enableval = xyes; then
+    ASSERTIONS=yes
+  fi
+fi
+
+if test x$ASSERTIONS = xno; then
+
+cat >>confdefs.h <<\_ACEOF
+#define NDEBUG 1
+_ACEOF
+
+fi
+
 WARNINGS=no
 # Check whether --enable-warnings was given.
 if test "${enable_warnings+set}" = set; then