diff --git a/ypsu.cpp b/ypsu.cpp
index 8a72d70..d80a207 100644
--- a/ypsu.cpp
+++ b/ypsu.cpp
@@ -196,17 +196,17 @@ static inline void mormord_sort_impl(uint32_t *a, int n, int j) noexcept {
 	uint32_t pivoti = 0;
 	while(pivoti < n) {
 		uint32_t radixval = morgrab(a[pivoti], j);
-		uint32_t targeti = radics[radixval] - 1;
+		uint32_t targeti = --radics[radixval]; // already dec index for swap
 		if(targeti > pivoti) {
 			// swap
 			uint32_t tmp = a[pivoti];
 			a[pivoti] = a[targeti];
 			a[targeti] = tmp;
-			// dec index
-			--radics[radixval];
 		} else {
 			// progress pivot
 			++pivoti;
+			// "undec" index
+			++radics[radixval];
 		}
 	}