diff --git a/SWIG/Lib/tcl/swigtcl8.swg b/SWIG/Lib/tcl/swigtcl8.swg
index 32965515e..a5f4d4283 100644
--- a/SWIG/Lib/tcl/swigtcl8.swg
+++ b/SWIG/Lib/tcl/swigtcl8.swg
@@ -795,6 +795,19 @@ typedef struct {
   char * (*set)(ClientData, Tcl_Interp *, char *, char *, int);
 } swig_var_info;
 
+
+/* Contract support */
+
+#define SWIG_preassert(expr, msg)  if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+#define SWIG_postassert(expr, msg) if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+
+#define SWIG_inherit_preassert(expr, msg)  if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+#define SWIG_inherit_postassert(expr, msg) if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+
+#define SWIG_invariant(expr, msg)       if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+#define SWIG_invariant_begin(expr, msg) if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+#define SWIG_invariant_end(expr, msg)   if (!(expr)) { Tcl_SetResult(interp, (char *) msg #expr, TCL_STATIC ); goto fail; } else
+
 #ifdef __cplusplus
 }
 #endif