diff --git a/src/game/common/thing/thing.cpp b/src/game/common/thing/thing.cpp
index d98d35ce1..0c708f97d 100644
--- a/src/game/common/thing/thing.cpp
+++ b/src/game/common/thing/thing.cpp
@@ -103,7 +103,8 @@ void Thing::Set_Position_Z(float z)
         React_To_Transform_Change(&old_tm, &old_pos, old_angle);
     }
 
-    captainslog_dbgassert(!gm_isnanf(Get_Position()->x) && !gm_isnanf(Get_Position()->y) && !gm_isnanf(Get_Position()->z),
+    captainslog_dbgassert(
+        !GameMath::Is_Nan(Get_Position()->x) && !GameMath::Is_Nan(Get_Position()->y) && !GameMath::Is_Nan(Get_Position()->z),
         "Drawable/Object position NAN! \'%s\'",
         m_template->Get_Name().Str());
 }
@@ -175,7 +176,8 @@ void Thing::Set_Orientation(float angle)
     m_cachedPos = pos;
     m_cacheFlags &= ~VALID_DIRVECTOR;
     React_To_Transform_Change(&old_tm, &old_pos, old_angle);
-    captainslog_dbgassert(!gm_isnanf(Get_Position()->x) && !gm_isnanf(Get_Position()->y) && !gm_isnanf(Get_Position()->z),
+    captainslog_dbgassert(
+        !GameMath::Is_Nan(Get_Position()->x) && !GameMath::Is_Nan(Get_Position()->y) && !GameMath::Is_Nan(Get_Position()->z),
         "Drawable/Object position NAN! \'%s\'",
         m_template->Get_Name().Str());
 }
@@ -198,7 +200,8 @@ void Thing::Set_Position(const Coord3D *pos)
         React_To_Transform_Change(&old_tm, &old_pos, old_angle);
     }
 
-    captainslog_dbgassert(!gm_isnanf(Get_Position()->x) && !gm_isnanf(Get_Position()->y) && !gm_isnanf(Get_Position()->z),
+    captainslog_dbgassert(
+        !GameMath::Is_Nan(Get_Position()->x) && !GameMath::Is_Nan(Get_Position()->y) && !GameMath::Is_Nan(Get_Position()->z),
         "Drawable/Object position NAN! \'%s\'",
         m_template->Get_Name().Str());
 }
@@ -216,7 +219,8 @@ void Thing::Set_Transform_Matrix(const Matrix3D *mx)
     m_cacheFlags = 0;
     React_To_Transform_Change(&old_tm, &old_pos, old_angle);
 
-    captainslog_dbgassert(!gm_isnanf(Get_Position()->x) && !gm_isnanf(Get_Position()->y) && !gm_isnanf(Get_Position()->z),
+    captainslog_dbgassert(
+        !GameMath::Is_Nan(Get_Position()->x) && !GameMath::Is_Nan(Get_Position()->y) && !GameMath::Is_Nan(Get_Position()->z),
         "Drawable/Object position NAN! \'%s\'",
         m_template->Get_Name().Str());
 }
diff --git a/src/game/logic/object/object.cpp b/src/game/logic/object/object.cpp
index 834b5b117..7083d1955 100644
--- a/src/game/logic/object/object.cpp
+++ b/src/game/logic/object/object.cpp
@@ -527,7 +527,7 @@ bool Angle_Changed(float f1, float f2)
 
 void Object::React_To_Transform_Change(const Matrix3D *tm, const Coord3D *pos, float angle)
 {
-    if (gm_isnanf(Get_Position()->x) || gm_isnanf(Get_Position()->y) || gm_isnanf(Get_Position()->z)) {
+    if (GameMath::Is_Nan(Get_Position()->x) || GameMath::Is_Nan(Get_Position()->y) || GameMath::Is_Nan(Get_Position()->z)) {
         captainslog_dbgassert(false, "Object pos is nan.");
         g_theGameLogic->Destroy_Object(this);
     }
diff --git a/src/game/logic/object/update/physicsupdate.cpp b/src/game/logic/object/update/physicsupdate.cpp
index c512d4d62..068a40bcf 100644
--- a/src/game/logic/object/update/physicsupdate.cpp
+++ b/src/game/logic/object/update/physicsupdate.cpp
@@ -258,7 +258,8 @@ UpdateSleepTime PhysicsBehavior::Update()
             tm.Adjust_Z_Translation(m_vel.z);
         }
 
-        if (gm_isnanf(tm.Get_X_Translation()) || gm_isnanf(tm.Get_Y_Translation()) || gm_isnanf(tm.Get_Z_Translation())) {
+        if (GameMath::Is_Nan(tm.Get_X_Translation()) || GameMath::Is_Nan(tm.Get_Y_Translation())
+            || GameMath::Is_Nan(tm.Get_Z_Translation())) {
             captainslog_dbgassert(false, "Object position is NAN, deleting.");
             g_theGameLogic->Destroy_Object(obj);
         }
@@ -570,7 +571,8 @@ void PhysicsBehavior::On_Collide(Object *other, Coord3D const *loc, Coord3D cons
                                     force.x = f3 * center_diff.x / f1;
                                     force.y = f3 * center_diff.y / f1;
                                     force.z = f3 * center_diff.z / f1;
-                                    captainslog_dbgassert(!gm_isnanf(force.x) && !gm_isnanf(force.y) && !gm_isnanf(force.z),
+                                    captainslog_dbgassert(!GameMath::Is_Nan(force.x) && !GameMath::Is_Nan(force.y)
+                                            && !GameMath::Is_Nan(force.z),
                                         "PhysicsBehavior::onCollide force NAN!");
                                     Apply_Force(&force);
                                 }
@@ -726,10 +728,10 @@ void PhysicsBehavior::Apply_Gravitational_Forces()
 
 void PhysicsBehavior::Apply_Force(const Coord3D *force)
 {
-    captainslog_dbgassert(
-        !gm_isnanf(force->x) && !gm_isnanf(force->y) && !gm_isnanf(force->z), "PhysicsBehavior::applyForce force NAN!");
+    captainslog_dbgassert(!GameMath::Is_Nan(force->x) && !GameMath::Is_Nan(force->y) && !GameMath::Is_Nan(force->z),
+        "PhysicsBehavior::applyForce force NAN!");
 
-    if (!gm_isnanf(force->x) && !gm_isnanf(force->y) && !gm_isnanf(force->z)) {
+    if (!GameMath::Is_Nan(force->x) && !GameMath::Is_Nan(force->y) && !GameMath::Is_Nan(force->z)) {
         float mass = Get_Mass();
         Coord3D new_force = *force;
 
diff --git a/src/w3d/math/gamemath.h b/src/w3d/math/gamemath.h
index fef2fc912..01ea304c7 100644
--- a/src/w3d/math/gamemath.h
+++ b/src/w3d/math/gamemath.h
@@ -66,24 +66,6 @@ extern const Array<float, ARC_TABLE_SIZE> _FastAsinTable;
 extern const Array<float, SIN_TABLE_SIZE> _FastSinTable;
 extern const Array<float, SIN_TABLE_SIZE> _FastInvSinTable;
 
-inline float Normalize_Angle(float angle)
-{
-    captainslog_dbgassert(!gm_isnanf(angle), "Angle is NAN in normalizeAngle!\n");
-    if (gm_isnanf(angle)) {
-        return 0.0f;
-    }
-
-    while (angle > GAMEMATH_PI) {
-        angle = angle - GAMEMATH_PI * 2;
-    }
-
-    while (angle <= -GAMEMATH_PI) {
-        angle = angle + GAMEMATH_PI * 2;
-    }
-
-    return angle;
-}
-
 namespace GameMath
 {
 void Init();
@@ -547,4 +529,31 @@ inline int Lrintf(float val)
 //    return true;
 //}
 
+inline bool Is_Nan(float val)
+{
+#ifdef BUILD_WITH_GAMEMATH
+    return gm_isnanf(val) != 0;
+#else
+    return std::isnan(val);
+#endif
+}
+
 } // namespace GameMath
+
+inline float Normalize_Angle(float angle)
+{
+    captainslog_dbgassert(!GameMath::Is_Nan(angle), "Angle is NAN in normalizeAngle!\n");
+    if (GameMath::Is_Nan(angle)) {
+        return 0.0f;
+    }
+
+    while (angle > GAMEMATH_PI) {
+        angle = angle - GAMEMATH_PI * 2;
+    }
+
+    while (angle <= -GAMEMATH_PI) {
+        angle = angle + GAMEMATH_PI * 2;
+    }
+
+    return angle;
+}