diff --git a/engines/falloc.c b/engines/falloc.c
index 525a0aa..4654fe8 100644
--- a/engines/falloc.c
+++ b/engines/falloc.c
@@ -44,7 +44,7 @@
 	if (f->fd == -1) {
 		char buf[FIO_VERROR_SIZE];
 		int __e = errno;
-		snprintf(buf, sizeof(buf) - 1, "open(%s)", f->file_name);
+		snprintf(buf, sizeof(buf), "open(%s)", f->file_name);
 		td_verror(td, __e, buf);
 	}
 
diff --git a/filesetup.c b/filesetup.c
index 6f0a876..5aadf12 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -563,7 +563,7 @@
 		if (__e == EMFILE && file_close_shadow_fds(td))
 			goto open_again;
 
-		snprintf(buf, sizeof(buf) - 1, "open(%s)", f->file_name);
+		snprintf(buf, sizeof(buf), "open(%s)", f->file_name);
 
 		if (__e == EINVAL && (flags & OS_O_DIRECT)) {
 			log_err("fio: looks like your file system does not " \
@@ -1250,7 +1250,7 @@
 	if (!D) {
 		char buf[FIO_VERROR_SIZE];
 
-		snprintf(buf, FIO_VERROR_SIZE - 1, "opendir(%s)", dirname);
+		snprintf(buf, FIO_VERROR_SIZE, "opendir(%s)", dirname);
 		td_verror(td, errno, buf);
 		return 1;
 	}
diff --git a/fio.h b/fio.h
index 2fd354a..d18029a 100644
--- a/fio.h
+++ b/fio.h
@@ -568,7 +568,7 @@
 		int e = (err);						\
 		(td)->error = e;					\
 		if (!(td)->first_error)					\
-			snprintf(td->verror, sizeof(td->verror) - 1, "file:%s:%d, func=%s, error=%s", __FILE__, __LINE__, (func), (msg));		\
+			snprintf(td->verror, sizeof(td->verror), "file:%s:%d, func=%s, error=%s", __FILE__, __LINE__, (func), (msg));		\
 	} while (0)
 
 
diff --git a/init.c b/init.c
index f0ad019..dfc5a8f 100644
--- a/init.c
+++ b/init.c
@@ -627,7 +627,7 @@
 		p++;
 	} while (*p);
 
-	snprintf(buf, 31, "%u%c", val, *p);
+	snprintf(buf, 32, "%u%c", val, *p);
 	return buf;
 }
 
diff --git a/iolog.c b/iolog.c
index 12f09d0..e4c1fef 100644
--- a/iolog.c
+++ b/iolog.c
@@ -534,7 +534,7 @@
 {
 	char file_name[256], *p;
 
-	snprintf(file_name, 200, "%s_%s.log", prefix, postfix);
+	snprintf(file_name, sizeof(file_name), "%s_%s.log", prefix, postfix);
 	p = basename(file_name);
 	__finish_log(log, p);
 }
diff --git a/log.c b/log.c
index af974f8..08509b3 100644
--- a/log.c
+++ b/log.c
@@ -12,6 +12,7 @@
 	size_t len;
 
 	len = vsnprintf(buffer, sizeof(buffer), str, args);
+	len = min(len, sizeof(buffer) - 1);
 
 	if (log_syslog)
 		syslog(LOG_INFO, "%s", buffer);
@@ -40,6 +41,7 @@
 	va_start(args, format);
 	len = vsnprintf(buffer, sizeof(buffer), format, args);
 	va_end(args);
+	len = min(len, sizeof(buffer) - 1);
 
 	if (log_syslog)
 		syslog(LOG_INFO, "%s", buffer);
@@ -58,6 +60,7 @@
 	va_start(args, format);
 	len = vsnprintf(buffer, sizeof(buffer), format, args);
 	va_end(args);
+	len = min(len, sizeof(buffer) - 1);
 
 	if (is_backend)
 		return fio_server_text_output(buffer, len);
@@ -77,6 +80,7 @@
 	va_start(args, format);
 	len = vsnprintf(buffer, sizeof(buffer), format, args);
 	va_end(args);
+	len = min(len, sizeof(buffer) - 1);
 
 	if (is_backend)
 		return fio_server_text_output(buffer, len);
diff --git a/server.c b/server.c
index 7ec8531..ad78572 100644
--- a/server.c
+++ b/server.c
@@ -811,6 +811,7 @@
 	va_start(args, format);
 	len = vsnprintf(buffer, sizeof(buffer), format, args);
 	va_end(args);
+	len = min(len, sizeof(buffer) - 1);
 
 	return fio_server_text_output(buffer, len);
 }
diff --git a/stat.c b/stat.c
index 7e2feea..62eee9a 100644
--- a/stat.c
+++ b/stat.c
@@ -753,7 +753,7 @@
 			json_object_add_value_int(percentile_object, "0.00", 0);
 			continue;
 		}
-		snprintf(buf, sizeof(buf) - 1, "%2.2f", ts->percentile_list[i].u.f);
+		snprintf(buf, sizeof(buf), "%2.2f", ts->percentile_list[i].u.f);
 		json_object_add_value_int(percentile_object, (const char *)buf, ovals[i]);
 	}
 
@@ -959,9 +959,9 @@
 	for (i = 0; i < 7; i++) {
 		char name[20];
 		if (i < 6)
-			snprintf(name, 19, "%d", 1 << i);
+			snprintf(name, 20, "%d", 1 << i);
 		else
-			snprintf(name, 19, ">=%d", 1 << i);
+			snprintf(name, 20, ">=%d", 1 << i);
 		json_object_add_value_float(tmp, (const char *)name, io_u_dist[i]);
 	}
 
diff --git a/t/log.c b/t/log.c
index ac02303..76ae68e 100644
--- a/t/log.c
+++ b/t/log.c
@@ -10,6 +10,7 @@
 	va_start(args, format);
 	len = vsnprintf(buffer, sizeof(buffer), format, args);
 	va_end(args);
+	len = min(len, sizeof(buffer) - 1);
 
 	return fwrite(buffer, len, 1, stderr);
 }
@@ -23,6 +24,7 @@
 	va_start(args, format);
 	len = vsnprintf(buffer, sizeof(buffer), format, args);
 	va_end(args);
+	len = min(len, sizeof(buffer) - 1);
 
 	return fwrite(buffer, len, 1, stdout);
 }