diff --git a/input/binary.c b/input/binary.c
index 9d7e1560..80820e02 100644
--- a/input/binary.c
+++ b/input/binary.c
@@ -25,7 +25,7 @@
 #include <sys/time.h>
 #include "sigrok.h"
 
-#define CHUNKSIZE          4096
+#define CHUNKSIZE             (512 * 1024)
 #define DEFAULT_NUM_PROBES    8
 
 static int format_match(const char *filename)
diff --git a/session_driver.c b/session_driver.c
index 27e8cdc9..b6d14eaa 100644
--- a/session_driver.c
+++ b/session_driver.c
@@ -27,7 +27,7 @@
 #include "sigrok-internal.h"
 
 /* size of payloads sent across the session bus */
-#define CHUNKSIZE 4096
+#define CHUNKSIZE (512 * 1024)
 
 struct session_vdevice {
 	char *capturefile;
diff --git a/sigrok-internal.h b/sigrok-internal.h
index 71325c27..4ea5d475 100644
--- a/sigrok-internal.h
+++ b/sigrok-internal.h
@@ -34,7 +34,7 @@
 #endif
 
 /* Size of a datastore chunk in units */
-#define DATASTORE_CHUNKSIZE 512000
+#define DATASTORE_CHUNKSIZE (512 * 1024)
 
 /*--- hwplugin.c ------------------------------------------------------------*/