diff --git a/include/math.hpp b/include/math.hpp
index 69651816..516cfdb5 100644
--- a/include/math.hpp
+++ b/include/math.hpp
@@ -76,7 +76,7 @@ inline void eucDivMod(int a, int b, int* div, int* mod) {
 }
 
 /** Returns `floor(log_2(n))`, or 0 if `n == 1`. */
-int log2(int n) {
+inline int log2(int n) {
 	int i = 0;
 	while (n >>= 1) {
 		i++;