diff --git a/repos/dde_linux/src/lib/usb/include/usb_nic_component.h b/repos/dde_linux/src/lib/usb/include/usb_nic_component.h
index 84f3ce1251..fd1da5973d 100644
--- a/repos/dde_linux/src/lib/usb/include/usb_nic_component.h
+++ b/repos/dde_linux/src/lib/usb/include/usb_nic_component.h
@@ -242,12 +242,10 @@ class Root : public Root_component
 
 			/*
 			 * Check if donated ram quota suffices for both communication
-			 * buffers. Also check both sizes separately to handle a
-			 * possible overflow of the sum of both sizes.
+			 * buffers and check for overflow
 			 */
-			if (tx_buf_size               > ram_quota - session_size
-			 || rx_buf_size               > ram_quota - session_size
-			 || tx_buf_size + rx_buf_size > ram_quota - session_size) {
+			if (tx_buf_size + rx_buf_size < tx_buf_size ||
+			    tx_buf_size + rx_buf_size > ram_quota - session_size) {
 				PERR("insufficient 'ram_quota', got %zd, need %zd",
 				     ram_quota, tx_buf_size + rx_buf_size + session_size);
 				throw Genode::Root::Quota_exceeded();
diff --git a/repos/dde_linux/src/lib/wifi/nic.cc b/repos/dde_linux/src/lib/wifi/nic.cc
index 27bc5f5f31..57d481607a 100644
--- a/repos/dde_linux/src/lib/wifi/nic.cc
+++ b/repos/dde_linux/src/lib/wifi/nic.cc
@@ -203,12 +203,10 @@ class Root : public Genode::Root_component<Wifi_session_component,
 
 			/*
 			 * Check if donated ram quota suffices for both communication
-			 * buffers. Also check both sizes separately to handle a
-			 * possible overflow of the sum of both sizes.
+			 * buffers and check for overflow
 			 */
-			if (tx_buf_size               > ram_quota - session_size
-			 || rx_buf_size               > ram_quota - session_size
-			 || tx_buf_size + rx_buf_size > ram_quota - session_size) {
+			if (tx_buf_size + rx_buf_size < tx_buf_size ||
+			    tx_buf_size + rx_buf_size > ram_quota - session_size) {
 				PERR("insufficient 'ram_quota', got %zd, need %zd",
 				     ram_quota, tx_buf_size + rx_buf_size + session_size);
 				throw Genode::Root::Quota_exceeded();
diff --git a/repos/os/include/nic/root.h b/repos/os/include/nic/root.h
index 7417170872..9993ee06b7 100644
--- a/repos/os/include/nic/root.h
+++ b/repos/os/include/nic/root.h
@@ -48,12 +48,10 @@ class Nic::Root : public Genode::Root_component<SESSION_COMPONENT,
 
 			/*
 			 * Check if donated ram quota suffices for both communication
-			 * buffers. Also check both sizes separately to handle a
-			 * possible overflow of the sum of both sizes.
+			 * buffers and check for overflow
 			 */
-			if (tx_buf_size               > ram_quota - session_size
-			 || rx_buf_size               > ram_quota - session_size
-			 || tx_buf_size + rx_buf_size > ram_quota - session_size) {
+			if (tx_buf_size + rx_buf_size < tx_buf_size ||
+			    tx_buf_size + rx_buf_size > ram_quota - session_size) {
 				PERR("insufficient 'ram_quota', got %zd, need %zd",
 				     ram_quota, tx_buf_size + rx_buf_size + session_size);
 				throw Genode::Root::Quota_exceeded();
diff --git a/repos/os/src/drivers/nic/spec/lan9118/main.cc b/repos/os/src/drivers/nic/spec/lan9118/main.cc
index 2099cbb081..2a5c428edf 100644
--- a/repos/os/src/drivers/nic/spec/lan9118/main.cc
+++ b/repos/os/src/drivers/nic/spec/lan9118/main.cc
@@ -52,12 +52,10 @@ class Root : public Genode::Root_component<Lan9118, Genode::Single_client>
 
 			/*
 			 * Check if donated ram quota suffices for both communication
-			 * buffers. Also check both sizes separately to handle a
-			 * possible overflow of the sum of both sizes.
+			 * buffers and check for overflow
 			 */
-			if (tx_buf_size               > ram_quota - session_size
-			 || rx_buf_size               > ram_quota - session_size
-			 || tx_buf_size + rx_buf_size > ram_quota - session_size) {
+			if (tx_buf_size + rx_buf_size < tx_buf_size ||
+			    tx_buf_size + rx_buf_size > ram_quota - session_size) {
 				PERR("insufficient 'ram_quota', got %zd, need %zd",
 				     ram_quota, tx_buf_size + rx_buf_size + session_size);
 				throw Genode::Root::Quota_exceeded();
diff --git a/repos/os/src/server/nic_loopback/main.cc b/repos/os/src/server/nic_loopback/main.cc
index 0e1a377947..e134ceec6c 100644
--- a/repos/os/src/server/nic_loopback/main.cc
+++ b/repos/os/src/server/nic_loopback/main.cc
@@ -166,12 +166,10 @@ class Nic::Root : public Genode::Root_component<Loopback_component>
 
 			/*
 			 * Check if donated ram quota suffices for both communication
-			 * buffers. Also check both sizes separately to handle a
-			 * possible overflow of the sum of both sizes.
+			 * buffers and check for overflow
 			 */
-			if (tx_buf_size               > ram_quota - session_size
-			 || rx_buf_size               > ram_quota - session_size
-			 || tx_buf_size + rx_buf_size > ram_quota - session_size) {
+			if (tx_buf_size + rx_buf_size < tx_buf_size ||
+			    tx_buf_size + rx_buf_size > ram_quota - session_size) {
 				PERR("insufficient 'ram_quota', got %zd, need %zd",
 				     ram_quota, tx_buf_size + rx_buf_size + session_size);
 				throw Root::Quota_exceeded();
diff --git a/repos/ports/src/app/openvpn/main.cc b/repos/ports/src/app/openvpn/main.cc
index c7852918a0..aeb03e02a3 100644
--- a/repos/ports/src/app/openvpn/main.cc
+++ b/repos/ports/src/app/openvpn/main.cc
@@ -230,12 +230,10 @@ class Root : public Genode::Root_component<Openvpn_component, Genode::Single_cli
 
 			/*
 			 * Check if donated ram quota suffices for both communication
-			 * buffers. Also check both sizes separately to handle a
-			 * possible overflow of the sum of both sizes.
+			 * buffers and check for overflow
 			 */
-			if (tx_buf_size               > ram_quota - session_size
-			 || rx_buf_size               > ram_quota - session_size
-			 || tx_buf_size + rx_buf_size > ram_quota - session_size) {
+			if (tx_buf_size + rx_buf_size < tx_buf_size ||
+			    tx_buf_size + rx_buf_size > ram_quota - session_size) {
 				PERR("insufficient 'ram_quota', got %zd, need %zd",
 				     ram_quota, tx_buf_size + rx_buf_size + session_size);
 				throw Genode::Root::Quota_exceeded();