diff --git a/libraries/animation/src/SwingTwistConstraint.cpp b/libraries/animation/src/SwingTwistConstraint.cpp
index 12d7e618e5..3d0e4e7c5f 100644
--- a/libraries/animation/src/SwingTwistConstraint.cpp
+++ b/libraries/animation/src/SwingTwistConstraint.cpp
@@ -388,7 +388,7 @@ void SwingTwistConstraint::dynamicallyAdjustLimits(const glm::quat& rotation) {
         glm::vec3 swungY = swingRotation * Vectors::UNIT_Y;
         glm::vec3 swingAxis = glm::cross(Vectors::UNIT_Y, swungY);
         float theta = atan2f(-swingAxis.z, swingAxis.x);
-        if (glm::isnan(theta)) {
+        if (isnan(theta)) {
             // atan2f() will only return NaN if either of its arguments is NaN, which can only
             // happen if we've been given a bad rotation.  Since a NaN value here could potentially
             // cause a crash (we use the value of theta to compute indices into a std::vector)
diff --git a/libraries/shared/src/PIDController.cpp b/libraries/shared/src/PIDController.cpp
index 647dd578e9..78aa31e4c7 100644
--- a/libraries/shared/src/PIDController.cpp
+++ b/libraries/shared/src/PIDController.cpp
@@ -34,7 +34,7 @@ float PIDController::update(float measuredValue, float dt, bool resetAccumulator
     if (getIsLogging()) {  // if logging/reporting
         updateHistory(measuredValue, dt, error, accumulatedError, changeInError, p, i, d, computedValue);
     }
-    Q_ASSERT(!glm::isnan(computedValue));
+    Q_ASSERT(!isnan(computedValue));
     
     // update state for next time
     _lastError = error;
diff --git a/libraries/shared/src/SettingHandle.cpp b/libraries/shared/src/SettingHandle.cpp
index 951d004318..4a2c0cf04b 100644
--- a/libraries/shared/src/SettingHandle.cpp
+++ b/libraries/shared/src/SettingHandle.cpp
@@ -18,7 +18,7 @@ void Settings::getFloatValueIfValid(const QString& name, float& floatValue) {
     const QVariant badDefaultValue = NAN;
     bool ok = true;
     float tempFloat = value(name, badDefaultValue).toFloat(&ok);
-    if (ok && !glm::isnan(tempFloat)) {
+    if (ok && !isnan(tempFloat)) {
         floatValue = tempFloat;
     }
 }
@@ -47,7 +47,7 @@ void Settings::getVec3ValueIfValid(const QString& name, glm::vec3& vecValue) {
         float x = value(QString("x"), badDefaultValue).toFloat(&ok);
         float y = value(QString("y"), badDefaultValue).toFloat(&ok);
         float z = value(QString("z"), badDefaultValue).toFloat(&ok);
-        if (ok && (!glm::isnan(x) && !glm::isnan(y) && !glm::isnan(z))) {
+        if (ok && (!isnan(x) && !isnan(y) && !isnan(z))) {
             vecValue = glm::vec3(x, y, z);
         }
     }
@@ -74,7 +74,7 @@ void Settings::getQuatValueIfValid(const QString& name, glm::quat& quatValue) {
         float y = value(QString("y"), badDefaultValue).toFloat(&ok);
         float z = value(QString("z"), badDefaultValue).toFloat(&ok);
         float w = value(QString("w"), badDefaultValue).toFloat(&ok);
-        if (ok && (!glm::isnan(x) && !glm::isnan(y) && !glm::isnan(z) && !glm::isnan(w))) {
+        if (ok && (!isnan(x) && !isnan(y) && !isnan(z) && !isnan(w))) {
             quatValue = glm::quat(w, x, y, z);
         }
     }