diff --git a/include/EffectEntry.h b/include/EffectEntry.h
index 6112cc3..df6cff6 100644
--- a/include/EffectEntry.h
+++ b/include/EffectEntry.h
@@ -4,7 +4,7 @@
 #include "Effect.h"
 
 typedef struct {
-  char* name;
+  const char* name;
   Effect* effect;
 } EffectEntry;
 
diff --git a/include/effect_animation.h b/include/effect_animation.h
index 789ccb2..4d06a6b 100644
--- a/include/effect_animation.h
+++ b/include/effect_animation.h
@@ -11,7 +11,7 @@ class AnimationEffect : public Effect {
     int frame = 0;
     CRGB background_color;
     int xOffset, yOffset;
-    long frameSince = 0;
+    unsigned long frameSince = 0;
   public:
     AnimationEffect(AnimationData *anim);
     AnimationEffect(AnimationData *anim, CRGB background_color);
diff --git a/include/effect_cycle.h b/include/effect_cycle.h
index 2ee891a..ad154c7 100644
--- a/include/effect_cycle.h
+++ b/include/effect_cycle.h
@@ -7,7 +7,7 @@
 class CycleEffect : public Effect {
   private:
     Effect* effect;
-    long effectSince = 0;
+    unsigned long effectSince = 0;
   public:
     void changeEffect();
 
diff --git a/include/effect_matrix.h b/include/effect_matrix.h
index 5afe8ec..838e9b7 100644
--- a/include/effect_matrix.h
+++ b/include/effect_matrix.h
@@ -11,9 +11,9 @@ class MatrixEffectColumn {
     int x, y;
     int length;
     Window* window;
-    int speed;
+    uint16_t speed;
     boolean running;
-    long last_move = 0;
+    unsigned long last_move = 0;
   public:
     MatrixEffectColumn();
     MatrixEffectColumn(Window* win, int xPos);
diff --git a/src/effect_bell.cpp b/src/effect_bell.cpp
index 38c4cd0..d77600e 100644
--- a/src/effect_bell.cpp
+++ b/src/effect_bell.cpp
@@ -8,7 +8,7 @@ void BellEffect::loop() {
     for (int y = 0; y < 16; y++) {
       for (int x = 0; x < 2; x++) {
         for (int z = 0; z < 8; z++) {
-          leds[XYsafe(x * 8 + z, y)] = sprite_bell[y * 2 + x] >> (7 - z) & 1 ^ invert ? color_on : color_off;
+          leds[XYsafe(x * 8 + z, y)] = (sprite_bell[y * 2 + x] >> (7 - z) & 1) ^ invert ? color_on : color_off;
         }
       }
     }
diff --git a/src/effect_big_clock.cpp b/src/effect_big_clock.cpp
index a117402..4407337 100644
--- a/src/effect_big_clock.cpp
+++ b/src/effect_big_clock.cpp
@@ -11,7 +11,7 @@ void BigClockEffect::drawNumber(uint8_t number, int x, int y, CRGB color) {
 }
 
 void BigClockEffect::drawText(char *text, int x, int y, CRGB color) {
-  for (int i = 0; i < strlen(text); i++) {
+  for (uint8_t i = 0; i < strlen(text); i++) {
     drawSprite(font_char(numbers4x7, text[i]), x + i * 4, y, color);
   }
 }
diff --git a/src/efffect_clock.cpp b/src/effect_clock.cpp
similarity index 100%
rename from src/efffect_clock.cpp
rename to src/effect_clock.cpp
diff --git a/src/fastled.cpp b/src/fastled.cpp
index 144842c..2c58b89 100644
--- a/src/fastled.cpp
+++ b/src/fastled.cpp
@@ -1,4 +1,3 @@
-#include <FastLED.h>
 #include "my_fastled.h"
 
 CRGB leds[LED_COUNT];
diff --git a/src/text.cpp b/src/text.cpp
index 08555b0..82d3911 100644
--- a/src/text.cpp
+++ b/src/text.cpp
@@ -20,7 +20,7 @@ void drawDigit(Window window, unsigned char* font, int w, int h, int x, int y, i
 }
 
 void drawText(Window window, char *font, int w, int h, char *text, int x, int y, CRGB color) {
-  for (int i = 0; i < strlen(text); i++) {
+  for (uint16_t i = 0; i < strlen(text); i++) {
     drawChar(window, font5x7, 5, 7, x+i*(w+1), y, text[i], color);
   }
 }