diff --git a/common/util.c b/common/util.c
index 243f90a8..25a3e861 100644
--- a/common/util.c
+++ b/common/util.c
@@ -1,3 +1,5 @@
+#include <math.h>
+
 #include "util.h"
 
 int wrap(int i, int max) {
@@ -5,13 +7,10 @@ int wrap(int i, int max) {
 }
 
 int numlen(int n) {
-	if (n >= 1000000) return 7;
-	if (n >= 100000) return 6;
-	if (n >= 10000) return 5;
-	if (n >= 1000) return 4;
-	if (n >= 100) return 3;
-	if (n >= 10) return 2;
-	return 1;
+	if (n == 0) {
+		return n;
+	}
+	return log10(n) + 1;
 }
 
 static struct modifier_key {
diff --git a/swaygrab/CMakeLists.txt b/swaygrab/CMakeLists.txt
index 9035ac8b..85ad3907 100644
--- a/swaygrab/CMakeLists.txt
+++ b/swaygrab/CMakeLists.txt
@@ -10,6 +10,7 @@ target_link_libraries(swaygrab
 	sway-common
 	${JSONC_LIBRARIES}
 	rt
+	m
 )
 
 install(