diff --git a/src/search/internal.h b/src/search/internal.h
index 2c1d501fd..0d69d2fab 100644
--- a/src/search/internal.h
+++ b/src/search/internal.h
@@ -33,10 +33,10 @@ typedef struct mc_search_cond_struct {
 
 /*** global variables defined in .c file *********************************************************/
 
-extern char STR_E_NOTFOUND[];
-extern char STR_E_UNKNOWN_TYPE[];
-extern char STR_E_RPL_NOT_EQ_TO_FOUND[];
-extern char STR_E_RPL_INVALID_TOKEN[];
+extern const char * STR_E_NOTFOUND;
+extern const char * STR_E_UNKNOWN_TYPE;
+extern const char * STR_E_RPL_NOT_EQ_TO_FOUND;
+extern const char * STR_E_RPL_INVALID_TOKEN;
 /*** declarations of public functions ************************************************************/
 
 
diff --git a/src/search/lib.c b/src/search/lib.c
index cea9e28b4..99db25bf0 100644
--- a/src/search/lib.c
+++ b/src/search/lib.c
@@ -36,10 +36,10 @@
 
 /*** global variables ****************************************************************************/
 
-char STR_E_NOTFOUND[] = N_(" Search string not found ");
-char STR_E_UNKNOWN_TYPE[] = N_(" Not implemented yet ");
-char STR_E_RPL_NOT_EQ_TO_FOUND[] = N_(" Num of replace tokens not equal to num of found tokens ");
-char STR_E_RPL_INVALID_TOKEN[] = N_(" Invalid token number %d ");
+const char * STR_E_NOTFOUND = N_(" Search string not found ");
+const char * STR_E_UNKNOWN_TYPE = N_(" Not implemented yet ");
+const char * STR_E_RPL_NOT_EQ_TO_FOUND = N_(" Num of replace tokens not equal to num of found tokens ");
+const char * STR_E_RPL_INVALID_TOKEN = N_(" Invalid token number %d ");
 
 /*** file scope macro definitions ****************************************************************/