diff --git a/src/mares_iconhd.c b/src/mares_iconhd.c
index 55d71c9..56aea79 100644
--- a/src/mares_iconhd.c
+++ b/src/mares_iconhd.c
@@ -193,7 +193,7 @@ mares_iconhd_packet (mares_iconhd_device_t *device,
 	};
 	status = dc_iostream_write (device->iostream, command, sizeof(command), NULL);
 	if (status != DC_STATUS_SUCCESS) {
-		ERROR (abstract->context, "Failed to send the command.");
+		ERROR (abstract->context, "Failed to send the command header.");
 		return status;
 	}
 
@@ -201,7 +201,7 @@ mares_iconhd_packet (mares_iconhd_device_t *device,
 	if (size) {
 		status = dc_iostream_write (device->iostream, data, size, NULL);
 		if (status != DC_STATUS_SUCCESS) {
-			ERROR (abstract->context, "Failed to send the command.");
+			ERROR (abstract->context, "Failed to send the command data.");
 			return status;
 		}
 	}
@@ -210,20 +210,20 @@ mares_iconhd_packet (mares_iconhd_device_t *device,
 	unsigned char header[1] = {0};
 	status = dc_iostream_read (device->iostream, header, sizeof (header), NULL);
 	if (status != DC_STATUS_SUCCESS) {
-		ERROR (abstract->context, "Failed to receive the answer.");
+		ERROR (abstract->context, "Failed to receive the packet header.");
 		return status;
 	}
 
 	// Verify the header byte.
 	if (header[0] != ACK) {
-		ERROR (abstract->context, "Unexpected answer byte.");
+		ERROR (abstract->context, "Unexpected packet header byte (%02x).", header[0]);
 		return DC_STATUS_PROTOCOL;
 	}
 
 	// Read the packet.
 	status = dc_iostream_read (device->iostream, answer, asize, NULL);
 	if (status != DC_STATUS_SUCCESS) {
-		ERROR (abstract->context, "Failed to receive the answer.");
+		ERROR (abstract->context, "Failed to receive the packet data.");
 		return status;
 	}
 
@@ -231,13 +231,13 @@ mares_iconhd_packet (mares_iconhd_device_t *device,
 	unsigned char trailer[1] = {0};
 	status = dc_iostream_read (device->iostream, trailer, sizeof (trailer), NULL);
 	if (status != DC_STATUS_SUCCESS) {
-		ERROR (abstract->context, "Failed to receive the answer.");
+		ERROR (abstract->context, "Failed to receive the packet trailer.");
 		return status;
 	}
 
 	// Verify the trailer byte.
 	if (trailer[0] != END) {
-		ERROR (abstract->context, "Unexpected answer byte.");
+		ERROR (abstract->context, "Unexpected packet trailer byte (%02x).", trailer[0]);
 		return DC_STATUS_PROTOCOL;
 	}