diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index 5b4513dc7..da2967a3c 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -5314,8 +5314,8 @@ uint16_t mode_2DJulia(void) {                           // An animated Julia set
   reAl = -0.94299f;               // PixelBlaze example
   imAg = 0.3162f;
 
-  reAl += sin_t((float)strip.now/305.f)/20.f;
-  imAg += sin_t((float)strip.now/405.f)/20.f;
+  reAl += (float)sin16_t(strip.now * 34) / 655340.f;
+  imAg += (float)sin16_t(strip.now * 26) / 655340.f;
 
   dx = (xmax - xmin) / (cols);     // Scale the delta x and y values to our matrix size.
   dy = (ymax - ymin) / (rows);
@@ -6279,6 +6279,7 @@ uint16_t mode_2Dplasmarotozoom() {
     }
   }
   *a -= 0.03f + float(SEGENV.speed-128)*0.0002f;  // rotation speed
+  if(*a < -6283.18530718f) *a += 6283.18530718f; // 1000*2*PI, protect sin/cos from very large input float values (will give wrong results)
 
   return FRAMETIME;
 }
diff --git a/wled00/wled_math.cpp b/wled00/wled_math.cpp
index 583381d66..a8ec55400 100644
--- a/wled00/wled_math.cpp
+++ b/wled00/wled_math.cpp
@@ -76,7 +76,7 @@ int16_t sin16_t(uint16_t theta) {
 }
 
 int16_t cos16_t(uint16_t theta) {
-  return sin16_t(theta + 16384); //cos(x) = sin(x+pi/2)
+  return sin16_t(theta + 0x4000); //cos(x) = sin(x+pi/2)
 }
 
 uint8_t sin8_t(uint8_t theta) {
@@ -98,7 +98,7 @@ float sin_approx(float theta) {
 
 float cos_approx(float theta) {
   uint16_t scaled_theta = (int)(theta * (float)(0xFFFF / M_TWOPI)); // note: do not cast negative float to uint! cast to int first (undefined on C3)
-  int32_t result = sin16_t(scaled_theta + 16384);
+  int32_t result = sin16_t(scaled_theta + 0x4000);
   float cos = float(result) / 0x7FFF;
   return cos;
 }