diff --git a/Source/cmListFileLexer.c b/Source/cmListFileLexer.c
index 6af37f1b3..f0f2ba75e 100644
--- a/Source/cmListFileLexer.c
+++ b/Source/cmListFileLexer.c
@@ -508,6 +508,7 @@ Modify cmListFileLexer.c:
 
 /* Disable features we do not need. */
 #define YY_NEVER_INTERACTIVE 1
+#define YY_NO_INPUT 1
 #define YY_NO_UNPUT 1
 #define YY_NO_UNISTD_H 1
 #define ECHO
diff --git a/Source/cmListFileLexer.in.l b/Source/cmListFileLexer.in.l
index 7587871fb..a28b9827d 100644
--- a/Source/cmListFileLexer.in.l
+++ b/Source/cmListFileLexer.in.l
@@ -34,6 +34,7 @@ Modify cmListFileLexer.c:
 
 /* Disable features we do not need. */
 #define YY_NEVER_INTERACTIVE 1
+#define YY_NO_INPUT 1
 #define YY_NO_UNPUT 1
 #define YY_NO_UNISTD_H 1
 #define ECHO