diff --git a/color_math.c b/color_math.c
index 831e216..af561ee 100644
--- a/color_math.c
+++ b/color_math.c
@@ -133,7 +133,7 @@ static double srgb_gamma(double value, double gamma) {
 	}
 }
 
-double clamp(double value) {
+static double clamp(double value) {
 	if (value > 1.0) {
 		return 1.0;
 	} else if (value < 0.0) {
diff --git a/color_math.h b/color_math.h
index 83bdfc8..c7739ce 100644
--- a/color_math.h
+++ b/color_math.h
@@ -24,6 +24,5 @@ struct sun {
 
 enum sun_condition calc_sun(struct tm *tm, double longitude, double latitude, struct sun *sun);
 void calc_whitepoint(int temp, double *rw, double *gw, double *bw);
-double clamp(double value);
 
 #endif
diff --git a/main.c b/main.c
index 37e1dde..c4fcd60 100644
--- a/main.c
+++ b/main.c
@@ -397,7 +397,12 @@ static int interpolate_temperature(time_t now, time_t start, time_t stop, int te
 	if (start == stop) {
 		return stop;
 	}
-	double time_pos = clamp((double)(now - start) / (double)(stop - start));
+	double time_pos = (double)(now - start) / (double)(stop - start);
+	if (time_pos > 1.0) {
+		time_pos = 1.0;
+	} else if (time_pos < 0.0) {
+		time_pos = 0.0;
+	}
 	int temp_pos = (double)(temp_stop - temp_start) * time_pos;
 	return temp_start + temp_pos;
 }