diff --git a/server/core/modutil.c b/server/core/modutil.c
index 5e6b1a8d3..c6bc9bd00 100644
--- a/server/core/modutil.c
+++ b/server/core/modutil.c
@@ -28,6 +28,7 @@
  * @endverbatim
  */
 #include <buffer.h>
+#include <string.h>
 
 /**
  * Check if a GWBUF structure is a MySQL COM_QUERY packet
@@ -75,6 +76,7 @@ char	*ptr;
         ptr += 2;  // Skip sequence id	and COM_QUERY byte
 	*length = *length - 1;
 	*sql = ptr;
+	return 1;
 }
 
 
@@ -86,7 +88,7 @@ int	length, newlength;
 GWBUF	*addition;
 
 	if (!modutil_is_SQL(orig))
-		return 0;
+		return NULL;
 	ptr = GWBUF_DATA(orig);
 	length = *ptr++;
 	length += (*ptr++ << 8);
diff --git a/server/modules/filter/qlafilter.c b/server/modules/filter/qlafilter.c
index 4e0ded1f9..520f1e1a9 100644
--- a/server/modules/filter/qlafilter.c
+++ b/server/modules/filter/qlafilter.c
@@ -259,7 +259,7 @@ struct timeval	tv;
 		gettimeofday(&tv, NULL);
 		localtime_r(&tv.tv_sec, &t);
 		sprintf(t_buf, "%02d:%02d:%02d.%-3d %d/%02d/%d, ",
-			t.tm_hour, t.tm_min, t.tm_sec, tv.tv_usec / 1000,
+			t.tm_hour, t.tm_min, t.tm_sec, (int)(tv.tv_usec / 1000),
 			t.tm_mday, t.tm_mon + 1, 1900 + t.tm_year);
 		write(my_session->fd, t_buf, strlen(t_buf));
 		write(my_session->fd, ptr, length);
@@ -285,7 +285,6 @@ struct timeval	tv;
 static	void
 diagnostic(FILTER *instance, void *fsession, DCB *dcb)
 {
-QLA_INSTANCE	*my_instance = (QLA_INSTANCE *)instance;
 QLA_SESSION	*my_session = (QLA_SESSION *)fsession;
 
 	if (my_session)
diff --git a/server/modules/filter/regexfilter.c b/server/modules/filter/regexfilter.c
index 882b1fd68..d45f2e105 100644
--- a/server/modules/filter/regexfilter.c
+++ b/server/modules/filter/regexfilter.c
@@ -164,7 +164,6 @@ int		i;
 static	void	*
 newSession(FILTER *instance, SESSION *session)
 {
-REGEX_INSTANCE	*my_instance = (REGEX_INSTANCE *)instance;
 REGEX_SESSION	*my_session;
 
 	if ((my_session = calloc(1, sizeof(REGEX_SESSION))) != NULL)