diff --git a/src/cc65/exprdesc.c b/src/cc65/exprdesc.c
index ea919dcc9..f31d4ef6b 100644
--- a/src/cc65/exprdesc.c
+++ b/src/cc65/exprdesc.c
@@ -110,3 +110,13 @@ void PrintExprDesc (FILE* F, ExprDesc* E)
 
 
 
+type* ReplaceType (ExprDesc* Expr, const type* NewType)
+/* Replace the type of Expr by a copy of Newtype and return the old type string */
+{
+    type* OldType = Expr->Type;
+    Expr->Type = TypeDup (NewType);
+    return OldType;
+}
+
+
+
diff --git a/src/cc65/exprdesc.h b/src/cc65/exprdesc.h
index 039a46ff8..bdd29f703 100644
--- a/src/cc65/exprdesc.h
+++ b/src/cc65/exprdesc.h
@@ -37,7 +37,7 @@
 #define EXPRDESC_H
 
 
-                     
+
 /* cc65 */
 #include "datatype.h"
 
@@ -94,6 +94,9 @@ void MakeConstIntExpr (ExprDesc* Expr, long Value);
 void PrintExprDesc (FILE* F, ExprDesc* Expr);
 /* Print an ExprDesc */
 
+type* ReplaceType (ExprDesc* Expr, const type* NewType);
+/* Replace the type of Expr by a copy of Newtype and return the old type string */
+
 
 
 /* End of exprdesc.h */