diff --git a/nfapi/oai_integration/nfapi.c b/nfapi/oai_integration/nfapi.c
index bf4be94526..57d5cab368 100644
--- a/nfapi/oai_integration/nfapi.c
+++ b/nfapi/oai_integration/nfapi.c
@@ -24,7 +24,7 @@
 #include "nfapi/oai_integration/vendor_ext.h"
 #include "common/utils/LOG/log.h"
 
-static char nfapi_str_mode[][24] = {
+static const char *const nfapi_str_mode[] = {
     "MONOLITHIC",
     "PNF",
     "VNF",
@@ -63,7 +63,7 @@ void set_thread_priority(int priority) {
   }
 }
 
-char *nfapi_get_strmode(void) {
+const char *nfapi_get_strmode(void) {
   if (nfapi_params.nfapi_mode > NFAPI_MODE_UNKNOWN)
     return nfapi_str_mode[NFAPI_MODE_UNKNOWN];
 
diff --git a/nfapi/oai_integration/vendor_ext.h b/nfapi/oai_integration/vendor_ext.h
index a1ca7e91bc..9a377dc27d 100644
--- a/nfapi/oai_integration/vendor_ext.h
+++ b/nfapi/oai_integration/vendor_ext.h
@@ -74,7 +74,7 @@ typedef enum {
   NFAPI_MODE_UNKNOWN
 } nfapi_mode_t;
 
-char *nfapi_get_strmode(void);
+const char *nfapi_get_strmode(void);
 void nfapi_logmode(void);
 nfapi_mode_t nfapi_getmode(void);
 void nfapi_setmode(nfapi_mode_t nfapi_mode);