diff --git a/lib/hostip.c b/lib/hostip.c
index 029019215b9933dfaddc529260a356373bb11522..f8c2be63fe754c6adbc9215bc0ac07007b03cd1e 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -524,7 +524,7 @@ int Curl_resolv_timeout(struct connectdata *conn,
                         const char *hostname,
                         int port,
                         struct Curl_dns_entry **entry,
-                        long timeout)
+                        volatile long timeout)
 {
 #ifdef USE_ALARM_TIMEOUT 
 #ifdef HAVE_SIGACTION
diff --git a/tests/server/tftpd.c b/tests/server/tftpd.c
index fc51b6effc8dcbcbf17281977adacd88dd413314..443eea970250161cde7f8700a9b826e01acad638 100644
--- a/tests/server/tftpd.c
+++ b/tests/server/tftpd.c
@@ -760,9 +760,9 @@ static void timer(int signum)
  */
 static void sendtftp(struct testcase *test, struct formats *pf)
 {
-  struct tftphdr *dp;
-  struct tftphdr *ap;    /* ack packet */
-  unsigned short block = 1;
+  struct tftphdr * volatile dp;
+  struct tftphdr * volatile ap;    /* ack packet */
+  volatile unsigned short block = 1;
   int size;
   ssize_t n;
 #if defined(HAVE_ALARM) && defined(SIGALRM)
@@ -835,9 +835,9 @@ static void justtimeout(int signum)
  */
 static void recvtftp(struct testcase *test, struct formats *pf)
 {
-  struct tftphdr *dp;
-  struct tftphdr *ap;    /* ack buffer */
-  unsigned short block = 0;
+  struct tftphdr * volatile dp;
+  struct tftphdr * volatile ap;    /* ack buffer */
+  volatile unsigned short block = 0;
   ssize_t n, size;
 #if defined(HAVE_ALARM) && defined(SIGALRM)
   mysignal(SIGALRM, timer);