3 files changed, 5 insertions, 3 deletions
diff --git a/include/lib/color.h b/include/lib/color.h
index 5e7128b..1bc9393 100644
--- a/include/lib/color.h
+++ b/include/lib/color.h
@@ -7,11 +7,11 @@
 
 // Color Equal to Background
 // Background: zeros in RGB, alpha can be whatever
-bool_t color_zero(uint8_t* color1, size_t channels);
+bool_t color_zero(const uint8_t* color1, size_t channels);
 
 // Color Equality
 // Determine if two colors are identical
-bool_t color_equal(uint8_t* color1, uint8_t* color2, size_t channels);
+bool_t color_equal(const uint8_t* color1, const uint8_t* color2, size_t channels);
 
 // Print out the `channels` length color vector
 void print_color(uint8_t* color, size_t channels);
diff --git a/include/lib/monad.h b/include/lib/monad.h
index 4a68e0a..74db079 100644
--- a/include/lib/monad.h
+++ b/include/lib/monad.h
@@ -1,6 +1,8 @@
 #ifndef INC_LIB_MONAD_H
 #define INC_LIB_MONAD_H
 
+#include <lib/bool.h>
+
 struct Result {
   void* data;
   bool_t success;
diff --git a/include/lib/time.h b/include/lib/time.h
index 9d69b44..1adf428 100644
--- a/include/lib/time.h
+++ b/include/lib/time.h
@@ -7,7 +7,7 @@
 
 // Difference in Time
 // Compute the difference between timespec structs
-double diff_time(struct timespec *time1, struct timespec *time0);
+double diff_time(const struct timespec *time1, const struct timespec *time0);
 
 // Get Current Time
 void get_time(struct timespec *ts);