diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index e827b2a810f7ba0619591e59a3ddfccca4055862..34aae82f1597c32ee10ff91a0ff4bc0bb5c0ddca 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -18453,8 +18453,7 @@ virDomainCachetuneDefParse(virDomainDefPtr def,
 
     /* We need to limit the bitmap to number of vCPUs.  If there's nothing left,
      * then we can just clean up and return 0 immediately */
-    if (virBitmapShrink(vcpus, def->maxvcpus) < 0)
-        goto cleanup;
+    virBitmapShrink(vcpus, def->maxvcpus);
 
     if (virBitmapIsAllClear(vcpus)) {
         ret = 0;
diff --git a/src/util/virbitmap.c b/src/util/virbitmap.c
index d1e5a9d1eacfd298a370dbd9bf8a02d037ee3a90..82b1f76427b6d2a62288fbb601af8e332f0b4a4b 100644
--- a/src/util/virbitmap.c
+++ b/src/util/virbitmap.c
@@ -1292,15 +1292,16 @@ virBitmapSubtract(virBitmapPtr a,
  * Reduces the bitmap to size @b.  Nothing will change if the size is already
  * smaller than or equal to @b.
  */
-int
+void
 virBitmapShrink(virBitmapPtr map,
                 size_t b)
 {
+    size_t toremove;
     size_t nl = 0;
     size_t nb = 0;
 
     if (!map)
-        return 0;
+        return;
 
     if (map->nbits >= b)
         map->nbits = b;
@@ -1309,14 +1310,13 @@ virBitmapShrink(virBitmapPtr map,
     nb = map->nbits % VIR_BITMAP_BITS_PER_UNIT;
     map->map[nl] &= ((1UL << nb) - 1);
 
-    nl++;
-    if (nl == map->map_len)
-        return 0;
+    toremove = map->map_alloc - (nl + 1);
 
-    if (VIR_REALLOC_N(map->map, nl) < 0)
-        return -1;
+    if (toremove == 0)
+        return;
 
-    map->map_len = nl;
-    map->map_alloc = nl;
-    return 0;
+    VIR_SHRINK_N(map->map, map->map_alloc, toremove);
+
+    /* length needs to be fixed as well */
+    map->map_len = map->map_alloc;
 }
diff --git a/src/util/virbitmap.h b/src/util/virbitmap.h
index 5a3362a19f9f8acb599a727c015c509e1c6c973d..2464814055de9d74edc7b834a7817d5ae5d3901a 100644
--- a/src/util/virbitmap.h
+++ b/src/util/virbitmap.h
@@ -153,6 +153,6 @@ void virBitmapIntersect(virBitmapPtr a, virBitmapPtr b)
 void virBitmapSubtract(virBitmapPtr a, virBitmapPtr b)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
-int virBitmapShrink(virBitmapPtr map, size_t b);
+void virBitmapShrink(virBitmapPtr map, size_t b);
 
 #endif
diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
index 6860e86e649d493b17e1f117b1469b2f2746d9c8..9639e004681aae1729e206e38e2a718cae58a857 100644
--- a/src/util/virresctrl.c
+++ b/src/util/virresctrl.c
@@ -952,8 +952,7 @@ virResctrlAllocParseProcessCache(virResctrlInfoPtr resctrl,
         goto cleanup;
     }
 
-    if (virBitmapShrink(mask, resctrl->levels[level]->types[type]->bits) < 0)
-        goto cleanup;
+    virBitmapShrink(mask, resctrl->levels[level]->types[type]->bits);
 
     if (virResctrlAllocUpdateMask(alloc, level, type, cache_id, mask) < 0)
         goto cleanup;
diff --git a/tests/virbitmaptest.c b/tests/virbitmaptest.c
index fffecdf1f6edbdfd6237e459e095ce185e6e82cf..2fbafc0a76321c447b7a3f3f79004b8b91dfb314 100644
--- a/tests/virbitmaptest.c
+++ b/tests/virbitmaptest.c
@@ -656,12 +656,10 @@ test12(const void *opaque ATTRIBUTE_UNUSED)
 
     TEST_MAP(1024, "34,1023");
 
-    if (virBitmapShrink(map, 35) < 0)
-        goto cleanup;
+    virBitmapShrink(map, 35);
     TEST_MAP(35, "34");
 
-    if (virBitmapShrink(map, 34) < 0)
-        goto cleanup;
+    virBitmapShrink(map, 34);
     TEST_MAP(34, "");
 
     ret = 0;