diff --git a/src/extract.c b/src/extract.c
index 8be05033..4488baae 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -164,7 +164,7 @@ int extract_tnef(struct session_data *sdata, struct parser_state *state, char *f
    struct dirent **namelist;
 
    memset(tmpdir, 0, sizeof(tmpdir));
-   make_random_string(&tmpdir[0], sizeof(tmpdir)-3);
+   make_random_string((unsigned char *)&tmpdir[0], sizeof(tmpdir)-3);
 
    memcpy(&tmpdir[sizeof(tmpdir)-3], ".d", 2);
 
diff --git a/src/misc.c b/src/misc.c
index ec961133..89a72a17 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -269,19 +269,18 @@ int extractEmail(char *rawmail, char *email){
  * using the rand() function if not possible
  */
 
-void make_random_string(char *buf, int buflen){
+void make_random_string(unsigned char *buf, int buflen){
    int i, len, fd;
    int urandom=0;
    static char alphanum[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
-   unsigned char s[QUEUE_ID_LEN];
 
    len = strlen(alphanum);
 
    fd = open(RANDOM_POOL, O_RDONLY);
    if(fd != -1){
-      if(readFromEntropyPool(fd, s, sizeof(s)) == sizeof(s)){
-         for(i=0; i<QUEUE_ID_LEN; i++){
-            *(buf+i) = alphanum[s[i] % len];
+      if(readFromEntropyPool(fd, buf, buflen) == buflen){
+         for(i=0; i<buflen; i++){
+            *(buf+i) = alphanum[*(buf+i) % len];
          }
 
          urandom = 1;
@@ -338,7 +337,7 @@ int get_random_bytes(unsigned char *buf, int len, unsigned char server_id){
    if(readFromEntropyPool(fd, buf+12+1, len-12-1) != len-12-1){
       syslog(LOG_PRIORITY, "%s: %s", ERR_CANNOT_READ_FROM_POOL, RANDOM_POOL);
    }
-   
+
    close(fd);
    return ret;
 }
diff --git a/src/misc.h b/src/misc.h
index 96481063..7cd650c9 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -26,7 +26,7 @@ char *split_str(char *row, char *what, char *s, int size);
 int trimBuffer(char *s);
 int extractEmail(char *rawmail, char *email);
 int extract_verp_address(char *email);
-void make_random_string(char *buf, int buflen);
+void make_random_string(unsigned char *buf, int buflen);
 void create_id(char *id, unsigned char server_id);
 int get_random_bytes(unsigned char *buf, int len, unsigned char server_id);
 int readFromEntropyPool(int fd, void *_s, ssize_t n);
diff --git a/src/smtp.c b/src/smtp.c
index db01f186..b0eb07b2 100644
--- a/src/smtp.c
+++ b/src/smtp.c
@@ -208,7 +208,7 @@ void process_command_mail_from(struct smtp_session *session, char *buf){
    }
    else {
       memset(&(session->ttmpfile[0]), 0, SMALLBUFSIZE);
-      make_random_string(&(session->ttmpfile[0]), QUEUE_ID_LEN);
+      make_random_string((unsigned char*)&(session->ttmpfile[0]), QUEUE_ID_LEN);
       session->protocol_state = SMTP_STATE_MAIL_FROM;
 
       extractEmail(buf, session->mailfrom);