diff --git a/lang/cem/cpp.ansi/LLlex.c b/lang/cem/cpp.ansi/LLlex.c
index 5b25a49d4..a0ec21a0f 100644
--- a/lang/cem/cpp.ansi/LLlex.c
+++ b/lang/cem/cpp.ansi/LLlex.c
@@ -7,6 +7,7 @@
 
 #include	"parameters.h"
 
+#include	<string.h>
 #include	<alloc.h>
 #include	"input.h"
 #include	"arith.h"