diff --git a/hal/src/main/native/cpp/jni/I2CJNI.cpp b/hal/src/main/native/cpp/jni/I2CJNI.cpp
index b605b9550a..68b844223a 100644
--- a/hal/src/main/native/cpp/jni/I2CJNI.cpp
+++ b/hal/src/main/native/cpp/jni/I2CJNI.cpp
@@ -64,6 +64,16 @@ Java_edu_wpi_first_hal_I2CJNI_i2CTransactionB
   (JNIEnv* env, jclass, jint port, jbyte address, jbyteArray dataToSend,
    jbyte sendSize, jbyteArray dataReceived, jbyte receiveSize)
 {
+  if (sendSize < 0) {
+    ThrowIllegalArgumentException(env, "I2CJNI.i2cTransactionB() sendSize < 0");
+    return 0;
+  }
+  if (receiveSize < 0) {
+    ThrowIllegalArgumentException(env,
+                                  "I2CJNI.i2cTransactionB() receiveSize < 0");
+    return 0;
+  }
+
   wpi::SmallVector<uint8_t, 128> recvBuf;
   recvBuf.resize(receiveSize);
   jint returnValue =
@@ -142,6 +152,11 @@ Java_edu_wpi_first_hal_I2CJNI_i2CReadB
   (JNIEnv* env, jclass, jint port, jbyte address, jbyteArray dataReceived,
    jbyte receiveSize)
 {
+  if (receiveSize < 0) {
+    ThrowIllegalArgumentException(env, "I2CJNI.i2cReadB() receiveSize < 0");
+    return 0;
+  }
+
   wpi::SmallVector<uint8_t, 128> recvBuf;
   recvBuf.resize(receiveSize);
   jint returnValue = HAL_ReadI2C(static_cast<HAL_I2CPort>(port), address,
diff --git a/hal/src/main/native/cpp/jni/SPIJNI.cpp b/hal/src/main/native/cpp/jni/SPIJNI.cpp
index 67ef56df44..3c9143bbb4 100644
--- a/hal/src/main/native/cpp/jni/SPIJNI.cpp
+++ b/hal/src/main/native/cpp/jni/SPIJNI.cpp
@@ -63,6 +63,11 @@ Java_edu_wpi_first_hal_SPIJNI_spiTransactionB
   (JNIEnv* env, jclass, jint port, jbyteArray dataToSend,
    jbyteArray dataReceived, jbyte size)
 {
+  if (size < 0) {
+    ThrowIllegalArgumentException(env, "SPIJNI.spiTransactionB() size < 0");
+    return 0;
+  }
+
   wpi::SmallVector<uint8_t, 128> recvBuf;
   recvBuf.resize(size);
   jint retVal =
@@ -120,6 +125,11 @@ Java_edu_wpi_first_hal_SPIJNI_spiRead
   (JNIEnv* env, jclass, jint port, jboolean initiate, jobject dataReceived,
    jbyte size)
 {
+  if (size < 0) {
+    ThrowIllegalArgumentException(env, "SPIJNI.spiRead() size < 0");
+    return 0;
+  }
+
   uint8_t* dataReceivedPtr =
       reinterpret_cast<uint8_t*>(env->GetDirectBufferAddress(dataReceived));
   jint retVal;
@@ -145,6 +155,11 @@ Java_edu_wpi_first_hal_SPIJNI_spiReadB
   (JNIEnv* env, jclass, jint port, jboolean initiate, jbyteArray dataReceived,
    jbyte size)
 {
+  if (size < 0) {
+    ThrowIllegalArgumentException(env, "SPIJNI.spiReadB() size < 0");
+    return 0;
+  }
+
   jint retVal;
   wpi::SmallVector<uint8_t, 128> recvBuf;
   recvBuf.resize(size);
@@ -361,6 +376,12 @@ Java_edu_wpi_first_hal_SPIJNI_spiReadAutoReceivedData__I_3IID
   (JNIEnv* env, jclass, jint port, jintArray buffer, jint numToRead,
    jdouble timeout)
 {
+  if (numToRead < 0) {
+    ThrowIllegalArgumentException(
+        env, "SPIJNI.spiReadAutoReceivedData() numToRead < 0");
+    return 0;
+  }
+
   wpi::SmallVector<uint32_t, 128> recvBuf;
   recvBuf.resize(numToRead);
   int32_t status = 0;