diff --git a/hit.c b/hit.c
index 33f9f3f..9dfa7a4 100644
--- a/hit.c
+++ b/hit.c
@@ -408,7 +408,33 @@ void mm_seg_free(void *km, int n_segs, mm_seg_t *segs)
 	kfree(km, segs);
 }
 
-void mm_set_mapq(int n_regs, mm_reg1_t *regs, int min_chain_sc, int match_sc, int rep_len, int is_sr)
+static void mm_set_inv_mapq(void *km, int n_regs, mm_reg1_t *regs)
+{
+	int i, n_aux;
+	uint64_t *aux;
+	if (n_regs < 3) return;
+	for (i = 0; i < n_regs; ++i)
+		if (regs[i].inv) break;
+	if (i == n_regs) return; // no inversion hits
+
+	aux = (uint64_t*)kmalloc(km, n_regs * 8);
+	for (i = n_aux = 0; i < n_regs; ++i)
+		if (regs[i].parent == i || regs[i].parent < 0)
+			aux[n_aux++] = (uint64_t)regs[i].as << 32 | i;
+	radix_sort_64(aux, aux + n_aux);
+
+	for (i = 1; i < n_aux - 1; ++i) {
+		mm_reg1_t *inv = &regs[(int32_t)aux[i]];
+		if (inv->inv) {
+			mm_reg1_t *l = &regs[(int32_t)aux[i-1]];
+			mm_reg1_t *r = &regs[(int32_t)aux[i+1]];
+			inv->mapq = l->mapq < r->mapq? l->mapq : r->mapq;
+		}
+	}
+	kfree(km, aux);
+}
+
+void mm_set_mapq(void *km, int n_regs, mm_reg1_t *regs, int min_chain_sc, int match_sc, int rep_len, int is_sr)
 {
 	static const float q_coef = 40.0f;
 	int64_t sum_sc = 0;
@@ -451,4 +477,5 @@ void mm_set_mapq(int n_regs, mm_reg1_t *regs, int min_chain_sc, int match_sc, in
 			if (r->p && r->p->dp_max > r->p->dp_max2 && r->mapq == 0) r->mapq = 1;
 		} else r->mapq = 0;
 	}
+	mm_set_inv_mapq(km, n_regs, regs);
 }
diff --git a/main.c b/main.c
index 6a0f333..4d1e45a 100644
--- a/main.c
+++ b/main.c
@@ -6,7 +6,7 @@
 #include "mmpriv.h"
 #include "getopt.h"
 
-#define MM_VERSION "2.8-r710-dirty"
+#define MM_VERSION "2.8-r711-dirty"
 
 #ifdef __linux__
 #include <sys/resource.h>
diff --git a/map.c b/map.c
index ad55cf8..4dcff71 100644
--- a/map.c
+++ b/map.c
@@ -340,7 +340,7 @@ void mm_map_frag(const mm_idx_t *mi, int n_segs, const int *qlens, const char **
 
 	if (n_segs == 1) { // uni-segment
 		regs0 = align_regs(opt, mi, b->km, qlens[0], seqs[0], &n_regs0, regs0, a);
-		mm_set_mapq(n_regs0, regs0, opt->min_chain_score, opt->a, rep_len, is_sr);
+		mm_set_mapq(b->km, n_regs0, regs0, opt->min_chain_score, opt->a, rep_len, is_sr);
 		n_regs[0] = n_regs0, regs[0] = regs0;
 	} else { // multi-segment
 		mm_seg_t *seg;
@@ -349,7 +349,7 @@ void mm_map_frag(const mm_idx_t *mi, int n_segs, const int *qlens, const char **
 		for (i = 0; i < n_segs; ++i) {
 			mm_set_parent(b->km, opt->mask_level, n_regs[i], regs[i], opt->a * 2 + opt->b); // update mm_reg1_t::parent
 			regs[i] = align_regs(opt, mi, b->km, qlens[i], seqs[i], &n_regs[i], regs[i], seg[i].a);
-			mm_set_mapq(n_regs[i], regs[i], opt->min_chain_score, opt->a, rep_len, is_sr);
+			mm_set_mapq(b->km, n_regs[i], regs[i], opt->min_chain_score, opt->a, rep_len, is_sr);
 		}
 		mm_seg_free(b->km, n_segs, seg);
 		if (n_segs == 2 && opt->pe_ori >= 0 && (opt->flag&MM_F_CIGAR))
diff --git a/mmpriv.h b/mmpriv.h
index 36c2033..3279695 100644
--- a/mmpriv.h
+++ b/mmpriv.h
@@ -78,7 +78,7 @@ void mm_select_sub_multi(void *km, float pri_ratio, float pri1, float pri2, int
 void mm_filter_regs(void *km, const mm_mapopt_t *opt, int qlen, int *n_regs, mm_reg1_t *regs);
 void mm_join_long(void *km, const mm_mapopt_t *opt, int qlen, int *n_regs, mm_reg1_t *regs, mm128_t *a);
 void mm_hit_sort_by_dp(void *km, int *n_regs, mm_reg1_t *r);
-void mm_set_mapq(int n_regs, mm_reg1_t *regs, int min_chain_sc, int match_sc, int rep_len, int is_sr);
+void mm_set_mapq(void *km, int n_regs, mm_reg1_t *regs, int min_chain_sc, int match_sc, int rep_len, int is_sr);
 
 void mm_est_err(const mm_idx_t *mi, int qlen, int n_regs, mm_reg1_t *regs, const mm128_t *a, int32_t n, const uint64_t *mini_pos);