diff --git a/src/p_map.c b/src/p_map.c
index 0a9107ee546239a47309d9600421ef4d1a6e29c7..2380a6d52452eacc83d00f25b530d09d5f7452e8 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -3107,7 +3107,7 @@ static void P_HitSlideLine(line_t *ld)
 	lineangle >>= ANGLETOFINESHIFT;
 	deltaangle >>= ANGLETOFINESHIFT;
 
-	movelen = P_AproxDistance(tmxmove, tmymove);
+	movelen = R_PointToDist2(0, 0, tmxmove, tmymove);
 	newlen = FixedMul(movelen, FINECOSINE(deltaangle));
 
 	tmxmove = FixedMul(newlen, FINECOSINE(lineangle));