diff --git a/sw/cheri/tests/i2c_tests.hh b/sw/cheri/tests/i2c_tests.hh
index c2907f537..5d2136cc6 100644
--- a/sw/cheri/tests/i2c_tests.hh
+++ b/sw/cheri/tests/i2c_tests.hh
@@ -197,7 +197,9 @@ int i2c_rpi_hat_id_eeprom_test(I2cPtr i2c) {
 
   // Send two 0x0000 byte addresses and skip the STOP condition.
   const uint8_t addr[] = {0, 0};
-  i2c->blocking_write(RpiHatIdEepromAddr, addr, sizeof(addr), true);
+  if (!i2c->blocking_write(RpiHatIdEepromAddr, addr, sizeof(addr), true)) {
+    return ++failures;  // If we can't write, then the read will block.
+  }
 
   // Fill a read buffer with dummy data so that we see changes.
   constexpr uint8_t DummyReadVal = 0x3D;
@@ -247,7 +249,9 @@ int i2c_rpi_hat_imu_whoami_test(I2cPtr i2c) {
 
   // Send the address and skip the STOP condition.
   const uint8_t addr[] = {RpiHatWhoAmIRegAddr};
-  i2c->blocking_write(RpiHatAccelGyroWhoAmIAddr, addr, sizeof(addr), true);
+  if (!i2c->blocking_write(RpiHatAccelGyroWhoAmIAddr, addr, sizeof(addr), true)) {
+    return ++failures;  // If we can't write, then the read will block.
+  }
 
   // Read from the `WHO_AM_I` register of the Accelerometer & Gyroscope,
   // and check it matches the expected value.
@@ -257,7 +261,9 @@ int i2c_rpi_hat_imu_whoami_test(I2cPtr i2c) {
   }
 
   // Send one 0x0F byte address and skip the STOP condition.
-  i2c->blocking_write(RpiHatIdMagneticWhoAmIAddr, addr, sizeof(addr), true);
+  if (!i2c->blocking_write(RpiHatIdMagneticWhoAmIAddr, addr, sizeof(addr), true)) {
+    return ++failures;  // If we can't write, then the read will block.
+  }
 
   // Read from the `WHO_AM_I` register of the Magnetic Sensor, and check
   // it matches the expected value.
@@ -287,7 +293,9 @@ int i2c_as6212_temperature_sense_test(I2cPtr i2c) {
 
   // Read from the config register, and check the dummy data was modified.
   uint8_t addr[] = {As6212ConfigRegAddr};
-  i2c->blocking_write(As6212Addr, addr, sizeof(addr), false);
+  if (!i2c->blocking_write(As6212Addr, addr, sizeof(addr), false)) {
+    return ++failures;  // If we can't write, then the read will block.
+  }
   uint8_t data[2] = {0xF0, 0x0F};
   if (!i2c->blocking_read(As6212Addr, data, 2U) || data[0] == 0xF0) {
     failures++;
@@ -295,7 +303,9 @@ int i2c_as6212_temperature_sense_test(I2cPtr i2c) {
 
   // Read from the temperature register
   addr[0] = As6212TempRegAddr;
-  i2c->blocking_write(As6212Addr, addr, sizeof(addr), false);
+  if (!i2c->blocking_write(As6212Addr, addr, sizeof(addr), false)) {
+    return ++failures;  // If we can't write, then the read will block.
+  }
   if (!i2c->blocking_read(As6212Addr, data, 2U)) {
     failures++;
   }
diff --git a/sw/cheri/tests/plic_tests.hh b/sw/cheri/tests/plic_tests.hh
index 9afb1d855..eadfd5ee3 100644
--- a/sw/cheri/tests/plic_tests.hh
+++ b/sw/cheri/tests/plic_tests.hh
@@ -88,7 +88,6 @@ struct PlicTest {
     };
     static constexpr std::array<i2c_irq, 15> i2cMap = {{
         {OpenTitanI2cInterrupt::ReceiveOverflow, true},
-        {OpenTitanI2cInterrupt::Nak, true},
         {OpenTitanI2cInterrupt::SclInterference, true},
         {OpenTitanI2cInterrupt::SdaInterference, true},
         {OpenTitanI2cInterrupt::StretchTimeout, true},
@@ -97,6 +96,7 @@ struct PlicTest {
         {OpenTitanI2cInterrupt::UnexpectedStop, true},
         {OpenTitanI2cInterrupt::HostTimeout, true},
 
+        {OpenTitanI2cInterrupt::ControllerHalt, false},
         {OpenTitanI2cInterrupt::TransmitStretch, false},
         {OpenTitanI2cInterrupt::AcquiredFull, false},
         {OpenTitanI2cInterrupt::TransmitThreshold, false},