diff --git a/proc/readproc.c b/proc/readproc.c
index 0eaa5c78..af02446d 100644
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -744,7 +744,8 @@ static char** file2strvec(const char* directory, const char* what) {
         #undef ARG_LEN
         if (end_of_file &&
             ((n > 0 && buf[n-1] != '\0') ||     /* last read char not null */
-             (n <= 0 && rbuf[tot-1] != '\0')))  /* last read char not null */
+             (n <= 0 && rbuf && rbuf[tot-1] != '\0')))  /* last read char not null */
+
             buf[n++] = '\0';                    /* so append null-terminator */
 
         if (n <= 0) break;         /* unneeded (end_of_file = 1) but avoid realloc */