diff --git a/wpimath/src/main/java/edu/wpi/first/math/controller/LinearQuadraticRegulator.java b/wpimath/src/main/java/edu/wpi/first/math/controller/LinearQuadraticRegulator.java
index 660fa8fefa..7ab4e62304 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/controller/LinearQuadraticRegulator.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/controller/LinearQuadraticRegulator.java
@@ -47,7 +47,7 @@ public class LinearQuadraticRegulator<States extends Num, Inputs extends Num, Ou
    * @param qelms The maximum desired error tolerance for each state.
    * @param relms The maximum desired control effort for each input.
    * @param dtSeconds Discretization timestep.
-   * @throws IllegalArgumentException If the system is uncontrollable.
+   * @throws IllegalArgumentException If the system is unstabilizable.
    */
   public LinearQuadraticRegulator(
       LinearSystem<States, Inputs, Outputs> plant,
@@ -74,7 +74,7 @@ public class LinearQuadraticRegulator<States extends Num, Inputs extends Num, Ou
    * @param qelms The maximum desired error tolerance for each state.
    * @param relms The maximum desired control effort for each input.
    * @param dtSeconds Discretization timestep.
-   * @throws IllegalArgumentException If the system is uncontrollable.
+   * @throws IllegalArgumentException If the system is unstabilizable.
    */
   public LinearQuadraticRegulator(
       Matrix<States, States> A,
@@ -98,7 +98,7 @@ public class LinearQuadraticRegulator<States extends Num, Inputs extends Num, Ou
    * @param Q The state cost matrix.
    * @param R The input cost matrix.
    * @param dtSeconds Discretization timestep.
-   * @throws IllegalArgumentException If the system is uncontrollable.
+   * @throws IllegalArgumentException If the system is unstabilizable.
    */
   public LinearQuadraticRegulator(
       Matrix<States, States> A,
@@ -112,7 +112,7 @@ public class LinearQuadraticRegulator<States extends Num, Inputs extends Num, Ou
 
     if (!StateSpaceUtil.isStabilizable(discA, discB)) {
       var msg =
-          "The system passed to the LQR is uncontrollable!\n\nA =\n"
+          "The system passed to the LQR is unstabilizable!\n\nA =\n"
               + discA.getStorage().toString()
               + "\nB =\n"
               + discB.getStorage().toString()
@@ -147,7 +147,7 @@ public class LinearQuadraticRegulator<States extends Num, Inputs extends Num, Ou
    * @param R The input cost matrix.
    * @param N The state-input cross-term cost matrix.
    * @param dtSeconds Discretization timestep.
-   * @throws IllegalArgumentException If the system is uncontrollable.
+   * @throws IllegalArgumentException If the system is unstabilizable.
    */
   public LinearQuadraticRegulator(
       Matrix<States, States> A,
diff --git a/wpimath/src/main/java/edu/wpi/first/math/estimator/KalmanFilter.java b/wpimath/src/main/java/edu/wpi/first/math/estimator/KalmanFilter.java
index 9e286255df..497f094668 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/estimator/KalmanFilter.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/estimator/KalmanFilter.java
@@ -59,7 +59,7 @@ public class KalmanFilter<States extends Num, Inputs extends Num, Outputs extend
    * @param stateStdDevs Standard deviations of model states.
    * @param measurementStdDevs Standard deviations of measurements.
    * @param dtSeconds Nominal discretization timestep.
-   * @throws IllegalArgumentException If the system is unobservable.
+   * @throws IllegalArgumentException If the system is undetectable.
    */
   public KalmanFilter(
       Nat<States> states,
@@ -87,7 +87,7 @@ public class KalmanFilter<States extends Num, Inputs extends Num, Outputs extend
 
     if (!StateSpaceUtil.isDetectable(discA, C)) {
       var msg =
-          "The system passed to the Kalman filter is unobservable!\n\nA =\n"
+          "The system passed to the Kalman filter is undetectable!\n\nA =\n"
               + discA.getStorage().toString()
               + "\nC =\n"
               + C.getStorage().toString()
diff --git a/wpimath/src/main/java/edu/wpi/first/math/estimator/SteadyStateKalmanFilter.java b/wpimath/src/main/java/edu/wpi/first/math/estimator/SteadyStateKalmanFilter.java
index e29032d7cb..6197304372 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/estimator/SteadyStateKalmanFilter.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/estimator/SteadyStateKalmanFilter.java
@@ -60,7 +60,7 @@ public class SteadyStateKalmanFilter<States extends Num, Inputs extends Num, Out
    * @param stateStdDevs Standard deviations of model states.
    * @param measurementStdDevs Standard deviations of measurements.
    * @param dtSeconds Nominal discretization timestep.
-   * @throws IllegalArgumentException If the system is unobservable.
+   * @throws IllegalArgumentException If the system is undetectable.
    */
   public SteadyStateKalmanFilter(
       Nat<States> states,
@@ -86,7 +86,7 @@ public class SteadyStateKalmanFilter<States extends Num, Inputs extends Num, Out
 
     if (!StateSpaceUtil.isDetectable(discA, C)) {
       var msg =
-          "The system passed to the Kalman filter is unobservable!\n\nA =\n"
+          "The system passed to the Kalman filter is undetectable!\n\nA =\n"
               + discA.getStorage().toString()
               + "\nC =\n"
               + C.getStorage().toString()
diff --git a/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.h b/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.h
index 8389a88a64..2671b3dccb 100644
--- a/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.h
+++ b/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.h
@@ -45,7 +45,7 @@ class LinearQuadraticRegulator {
    * @param Qelems The maximum desired error tolerance for each state.
    * @param Relems The maximum desired control effort for each input.
    * @param dt     Discretization timestep.
-   * @throws std::invalid_argument If the system is uncontrollable.
+   * @throws std::invalid_argument If the system is unstabilizable.
    */
   template <int Outputs>
   LinearQuadraticRegulator(const LinearSystem<States, Inputs, Outputs>& plant,
@@ -64,7 +64,7 @@ class LinearQuadraticRegulator {
    * @param Qelems The maximum desired error tolerance for each state.
    * @param Relems The maximum desired control effort for each input.
    * @param dt     Discretization timestep.
-   * @throws std::invalid_argument If the system is uncontrollable.
+   * @throws std::invalid_argument If the system is unstabilizable.
    */
   LinearQuadraticRegulator(const Matrixd<States, States>& A,
                            const Matrixd<States, Inputs>& B,
@@ -79,7 +79,7 @@ class LinearQuadraticRegulator {
    * @param Q  The state cost matrix.
    * @param R  The input cost matrix.
    * @param dt Discretization timestep.
-   * @throws std::invalid_argument If the system is uncontrollable.
+   * @throws std::invalid_argument If the system is unstabilizable.
    */
   LinearQuadraticRegulator(const Matrixd<States, States>& A,
                            const Matrixd<States, Inputs>& B,
@@ -96,7 +96,7 @@ class LinearQuadraticRegulator {
    * @param R  The input cost matrix.
    * @param N  The state-input cross-term cost matrix.
    * @param dt Discretization timestep.
-   * @throws std::invalid_argument If the system is uncontrollable.
+   * @throws std::invalid_argument If the system is unstabilizable.
    */
   LinearQuadraticRegulator(const Matrixd<States, States>& A,
                            const Matrixd<States, Inputs>& B,
diff --git a/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.inc b/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.inc
index 1871244db5..333181ce49 100644
--- a/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.inc
+++ b/wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.inc
@@ -44,8 +44,7 @@ LinearQuadraticRegulator<States, Inputs>::LinearQuadraticRegulator(
 
   if (!IsStabilizable<States, Inputs>(discA, discB)) {
     std::string msg = fmt::format(
-        "The system passed to the LQR is uncontrollable!\n\nA =\n{}\nB "
-        "=\n{}\n",
+        "The system passed to the LQR is unstabilizable!\n\nA =\n{}\nB =\n{}\n",
         discA, discB);
 
     wpi::math::MathSharedStore::ReportError(msg);
diff --git a/wpimath/src/main/native/include/frc/estimator/KalmanFilter.h b/wpimath/src/main/native/include/frc/estimator/KalmanFilter.h
index 56dce0c11c..54ee51bafc 100644
--- a/wpimath/src/main/native/include/frc/estimator/KalmanFilter.h
+++ b/wpimath/src/main/native/include/frc/estimator/KalmanFilter.h
@@ -55,7 +55,7 @@ class KalmanFilter {
    * @param stateStdDevs       Standard deviations of model states.
    * @param measurementStdDevs Standard deviations of measurements.
    * @param dt                 Nominal discretization timestep.
-   * @throws std::invalid_argument If the system is unobservable.
+   * @throws std::invalid_argument If the system is undetectable.
    */
   KalmanFilter(LinearSystem<States, Inputs, Outputs>& plant,
                const StateArray& stateStdDevs,
diff --git a/wpimath/src/main/native/include/frc/estimator/KalmanFilter.inc b/wpimath/src/main/native/include/frc/estimator/KalmanFilter.inc
index cfb8bd9bf9..a00b455b31 100644
--- a/wpimath/src/main/native/include/frc/estimator/KalmanFilter.inc
+++ b/wpimath/src/main/native/include/frc/estimator/KalmanFilter.inc
@@ -41,8 +41,8 @@ KalmanFilter<States, Inputs, Outputs>::KalmanFilter(
 
   if (!IsDetectable<States, Outputs>(discA, C)) {
     std::string msg = fmt::format(
-        "The system passed to the Kalman filter is "
-        "unobservable!\n\nA =\n{}\nC =\n{}\n",
+        "The system passed to the Kalman filter is undetectable!\n\n"
+        "A =\n{}\nC =\n{}\n",
         discA, C);
 
     wpi::math::MathSharedStore::ReportError(msg);
diff --git a/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.h b/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.h
index 64b1782b97..0604541561 100644
--- a/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.h
+++ b/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.h
@@ -58,7 +58,7 @@ class SteadyStateKalmanFilter {
    * @param stateStdDevs       Standard deviations of model states.
    * @param measurementStdDevs Standard deviations of measurements.
    * @param dt                 Nominal discretization timestep.
-   * @throws std::invalid_argument If the system is unobservable.
+   * @throws std::invalid_argument If the system is undetectable.
    */
   SteadyStateKalmanFilter(LinearSystem<States, Inputs, Outputs>& plant,
                           const StateArray& stateStdDevs,
diff --git a/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.inc b/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.inc
index 1f2f2a2ff6..2f75b241cc 100644
--- a/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.inc
+++ b/wpimath/src/main/native/include/frc/estimator/SteadyStateKalmanFilter.inc
@@ -39,8 +39,8 @@ SteadyStateKalmanFilter<States, Inputs, Outputs>::SteadyStateKalmanFilter(
 
   if (!IsDetectable<States, Outputs>(discA, C)) {
     std::string msg = fmt::format(
-        "The system passed to the Kalman filter is "
-        "unobservable!\n\nA =\n{}\nC =\n{}\n",
+        "The system passed to the Kalman filter is undetectable!\n\n"
+        "A =\n{}\nC =\n{}\n",
         discA, C);
 
     wpi::math::MathSharedStore::ReportError(msg);