diff --git a/src/common/ioutil.c b/src/common/ioutil.c
index 6dbc3c5..6a8309a 100644
--- a/src/common/ioutil.c
+++ b/src/common/ioutil.c
@@ -31,8 +31,6 @@ int build_allocation_map(struct bitset * allocation_map, int fd)
 
 	for (offset = 0; offset < allocation_map->size; ) {
 
-		unsigned int i;
-
 		fiemap->fm_start = offset;
 
 		fiemap->fm_length = max_length;
@@ -49,7 +47,7 @@ int build_allocation_map(struct bitset * allocation_map, int fd)
 			return 0; /* it's up to the caller to free the map */
 		}
 		else {
-			for ( i = 0; i < fiemap->fm_mapped_extents; i++ ) {
+			for ( unsigned int i = 0; i < fiemap->fm_mapped_extents; i++ ) {
 				bitset_set_range( allocation_map,
 						  fiemap->fm_extents[i].fe_logical,
 						  fiemap->fm_extents[i].fe_length );
diff --git a/src/common/self_pipe.c b/src/common/self_pipe.c
index 12bc3f2..0999b11 100644
--- a/src/common/self_pipe.c
+++ b/src/common/self_pipe.c
@@ -51,7 +51,6 @@ struct self_pipe * self_pipe_create(void)
 {
 	struct self_pipe *sig = xmalloc( sizeof( struct self_pipe ) );
 	int fds[2];
-	int fcntl_err;
 	
 	if ( NULL == sig ) { return NULL; }
 
@@ -62,7 +61,7 @@ struct self_pipe * self_pipe_create(void)
 	}
 
 	if ( fcntl( fds[0], F_SETFL, O_NONBLOCK ) || fcntl( fds[1], F_SETFL, O_NONBLOCK ) ) {
-		fcntl_err = errno;
+		int fcntl_err = errno;
 		while( close( fds[0] ) == -1 && errno == EINTR );
 		while( close( fds[1] ) == -1 && errno == EINTR );
 		free( sig );
diff --git a/src/common/serve.c b/src/common/serve.c
index 93e6014..649bd5e 100644
--- a/src/common/serve.c
+++ b/src/common/serve.c
@@ -233,7 +233,6 @@ int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthre
 
 	int was_closed = 0;
 	void * status=NULL;
-	int join_errno;
 
 	if (entry->thread != 0) {
 		char s_client_address[128];
@@ -241,7 +240,7 @@ int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthre
 		sockaddr_address_string( &entry->address.generic, &s_client_address[0], 128 );
 
 		debug( "%s(%p,...)", joinfunc == pthread_join ? "joining" : "tryjoining", entry->thread );
-		join_errno = joinfunc(entry->thread, &status);
+		int join_errno = joinfunc(entry->thread, &status);
 
 		/* join_errno can legitimately be ESRCH if the thread is
 		 * already dead, but the client still needs tidying up. */
@@ -598,7 +597,6 @@ int server_accept( struct server * params )
 {
 	NULLCHECK( params );
 	debug("accept loop starting");
-	int              client_fd;
 	union mysockaddr client_address;
 	fd_set           fds;
 	socklen_t        socklen=sizeof(client_address);
@@ -638,7 +636,7 @@ int server_accept( struct server * params )
 	}
 
 	if ( FD_ISSET( params->server_fd, &fds ) ){
-		client_fd = accept( params->server_fd, &client_address.generic, &socklen );
+		int client_fd = accept( params->server_fd, &client_address.generic, &socklen );
 
 		if ( params->allow_new_clients ) {
 			debug("Accepted nbd client socket fd %d", client_fd);
@@ -741,11 +739,11 @@ void server_join_clients( struct server * serve ) {
 
 	for (i=0; i < serve->max_nbd_clients; i++) {
 		pthread_t thread_id = serve->nbd_client[i].thread;
-		int err = 0;
 
 		if (thread_id != 0) {
 			debug( "joining thread %p", thread_id );
-			if ( 0 == (err = pthread_join( thread_id, &status ) ) ) {
+			int err = pthread_join( thread_id, &status );
+			if ( 0 == err ) {
 				serve->nbd_client[i].thread = 0;
 			} else {
 				warn( "Error %s (%i) joining thread %p", strerror( err ), err, thread_id );
diff --git a/src/common/sockutil.c b/src/common/sockutil.c
index 001f3a3..1377958 100644
--- a/src/common/sockutil.c
+++ b/src/common/sockutil.c
@@ -39,7 +39,6 @@ const char* sockaddr_address_string( const struct sockaddr* sa, char* dest, size
 	struct sockaddr_un*  un  = ( struct sockaddr_un*  ) sa;
 
 	unsigned short real_port = ntohs( in->sin_port ); // common to in and in6
-	size_t size;
 	const char* ret = NULL;
 
 	memset( dest, 0, len );
@@ -57,7 +56,7 @@ const char* sockaddr_address_string( const struct sockaddr* sa, char* dest, size
 	}
 
 	if ( NULL != ret && real_port > 0 && sa->sa_family != AF_UNIX ) {
-		size = strlen( dest );
+		size_t size = strlen( dest );
 		snprintf( dest + size, len - size, " port %d", real_port );
 	}