diff --git a/coverager.c b/coverager.c
index 3fc143a..f48d788 100644
--- a/coverager.c
+++ b/coverager.c
@@ -171,9 +171,13 @@ static void xc_coverager_save_cov(char *srcfile, char *outfilename, coverager_t
 	p[0] = 0;
 	p[1] = covlines;
 
-	ftruncate(fd, 0);
+	if (ftruncate(fd, 0) != 0) {
+		goto bailout;
+	}
 	lseek(fd, 0, SEEK_SET);
-	write(fd, (char *) buf, size);
+	if (write(fd, (char *) buf, size) != size) {
+		goto bailout;
+	}
 
 bailout:
 	if (contents) efree(contents);
diff --git a/mmap.c b/mmap.c
index b99f29b..a8d4af2 100644
--- a/mmap.c
+++ b/mmap.c
@@ -186,7 +186,12 @@ static XC_SHM_INIT(xc_mmap_init) /* {{{ */
 			goto err;
 		}
 	}
-	ftruncate(fd, size);
+
+	if (ftruncate(fd, size) != 0) {
+		perror(shm->name);
+		errstr = "Failed to ftruncate the file";
+		goto err;
+	}
 #endif
 
 #ifdef ZEND_WIN32
diff --git a/xcache.c b/xcache.c
index 5abf724..afc4c17 100644
--- a/xcache.c
+++ b/xcache.c
@@ -3155,7 +3155,10 @@ static void xcache_signal_handler(int sig) /* {{{ */
 {
 	xcache_restore_signal_handler();
 	if (xc_coredump_dir && xc_coredump_dir[0]) {
-		chdir(xc_coredump_dir);
+		if (chdir(xc_coredump_dir) != 0) {
+			/* error, but nothing can do about it
+			 * and should'nt print anything which might SEGV again */
+		}
 	}
 	raise(sig);
 }