diff --git a/roaring/roaring.go b/roaring/roaring.go
index 743513562..3eca20357 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -1156,8 +1156,11 @@ func (c *container) runAdd(v uint32) bool {
 func (c *container) contains(v uint32) bool {
 	if c.isArray() {
 		return c.arrayContains(v)
+	} else if c.isBitmap() {
+		return c.bitmapContains(v)
+	} else {
+		return c.runContains(v)
 	}
-	return c.bitmapContains(v)
 }
 
 func (c *container) arrayContains(v uint32) bool {
@@ -1183,11 +1186,18 @@ func (c *container) runContains(v uint32) bool {
 }
 
 // remove adds a value to the container.
-func (c *container) remove(v uint32) bool {
+func (c *container) remove(v uint32) (removed bool) {
 	if c.isArray() {
-		return c.arrayRemove(v)
+		removed = c.arrayRemove(v)
+	} else if c.isBitmap() {
+		removed = c.bitmapRemove(v)
+	} else {
+		removed = c.runRemove(v)
 	}
-	return c.bitmapRemove(v)
+	if removed {
+		c.n--
+	}
+	return removed
 }
 
 func (c *container) arrayRemove(v uint32) bool {
@@ -1197,7 +1207,6 @@ func (c *container) arrayRemove(v uint32) bool {
 	}
 	c.unmap()
 
-	c.n--
 	c.array = append(c.array[:i], c.array[i+1:]...)
 	return true
 }
@@ -1219,6 +1228,30 @@ func (c *container) bitmapRemove(v uint32) bool {
 	return true
 }
 
+func (c *container) runRemove(v uint32) bool {
+	v16 := uint16(v)
+	for i, iv := range c.runs {
+		if v16 <= iv.last {
+			if v16 < iv.start {
+				return false
+			}
+			c.unmap()
+			if v16 == iv.last && v16 == iv.start {
+				c.runs = append(c.runs[:i], c.runs[i+1:]...)
+			} else if v16 == iv.last {
+				c.runs[i].last -= 1
+			} else if v16 == iv.start {
+				c.runs[i].start += 1
+			} else if v16 > iv.start {
+				c.runs[i].last = v16 - 1
+				c.runs = append(c.runs[:i+1], append([]interval16{{start: v16 + 1, last: iv.last}}, c.runs[i+1:]...)...)
+			}
+			return true
+		}
+	}
+	return false
+}
+
 // max returns the maximum value in the container.
 func (c *container) max() uint32 {
 	if c.isArray() {
diff --git a/roaring/roaring_internal_test.go b/roaring/roaring_internal_test.go
index c9a7160cd..c5736ea11 100644
--- a/roaring/roaring_internal_test.go
+++ b/roaring/roaring_internal_test.go
@@ -47,6 +47,7 @@ func TestContainerRunAdd(t *testing.T) {
 		{8, []interval16{{start: 0, last: 4}, {start: 6, last: 8}, {start: 10, last: 10}}},
 	}
 	for _, test := range tests {
+		c.mapped = true
 		ret := c.add(test.op)
 		if !ret {
 			t.Fatalf("result of adding new bit should be true: %v", c.runs)
@@ -54,6 +55,9 @@ func TestContainerRunAdd(t *testing.T) {
 		if !reflect.DeepEqual(c.runs, test.exp) {
 			t.Fatalf("Should have %v, but got %v after adding %v", test.exp, c.runs, test.op)
 		}
+		if c.mapped {
+			t.Fatalf("container should not be mapped after adding bit %v", test.op)
+		}
 	}
 }
 
@@ -221,3 +225,37 @@ func TestIntersectionCountArrayBitmap2(t *testing.T) {
 		}
 	}
 }
+
+func TestRunRemove(t *testing.T) {
+	c := container{runs: []interval16{{start: 2, last: 10}, {start: 12, last: 13}, {start: 15, last: 16}}}
+	tests := []struct {
+		op     uint32
+		exp    []interval16
+		expRet bool
+	}{
+		{2, []interval16{{start: 3, last: 10}, {start: 12, last: 13}, {start: 15, last: 16}}, true},
+		{10, []interval16{{start: 3, last: 9}, {start: 12, last: 13}, {start: 15, last: 16}}, true},
+		{12, []interval16{{start: 3, last: 9}, {start: 13, last: 13}, {start: 15, last: 16}}, true},
+		{13, []interval16{{start: 3, last: 9}, {start: 15, last: 16}}, true},
+		{16, []interval16{{start: 3, last: 9}, {start: 15, last: 15}}, true},
+		{6, []interval16{{start: 3, last: 5}, {start: 7, last: 9}, {start: 15, last: 15}}, true},
+		{8, []interval16{{start: 3, last: 5}, {start: 7, last: 7}, {start: 9, last: 9}, {start: 15, last: 15}}, true},
+		{8, []interval16{{start: 3, last: 5}, {start: 7, last: 7}, {start: 9, last: 9}, {start: 15, last: 15}}, false},
+		{1, []interval16{{start: 3, last: 5}, {start: 7, last: 7}, {start: 9, last: 9}, {start: 15, last: 15}}, false},
+		{44, []interval16{{start: 3, last: 5}, {start: 7, last: 7}, {start: 9, last: 9}, {start: 15, last: 15}}, false},
+	}
+
+	for _, test := range tests {
+		c.mapped = true
+		ret := c.remove(test.op)
+		if ret != test.expRet || !reflect.DeepEqual(c.runs, test.exp) {
+			t.Fatalf("Unexpected result removing %v from runs. Expected %v, got %v. Expected %v, got %v", test.op, test.expRet, ret, test.exp, c.runs)
+		}
+		if ret && c.mapped {
+			t.Fatalf("container was not unmapped although bit %v was removed", test.op)
+		}
+		if !ret && !c.mapped {
+			t.Fatalf("container was unmapped although bit %v was not removed", test.op)
+		}
+	}
+}