diff --git a/roaring/roaring.go b/roaring/roaring.go
index 520a5ffe8..5cb592881 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -431,6 +431,12 @@ func (b *Bitmap) Size() int {
 
 // CountRange returns the number of bits set between [start, end).
 func (b *Bitmap) CountRange(start, end uint64) (n uint64) {
+	if roaringParanoia {
+		if start > end {
+			panic(fmt.Sprintf("counting in range but %v > %v", start, end))
+		}
+	}
+
 	if b.Containers.Size() == 0 {
 		return
 	}
@@ -452,11 +458,7 @@ func (b *Bitmap) CountRange(start, end uint64) (n uint64) {
 			// TODO remove once we've validated this stuff works
 			panic("should be impossible for k to be less than skey")
 		}
-		if roaringParanoia {
-			if start > end {
-				panic(fmt.Sprintf("counting in range but %v > %v", start, end))
-			}
-		}
+
 		// k > ekey handles the case when start > end and where start and end
 		// are in different containers. Same container case is already handled above.
 		if k > ekey {
@@ -1380,6 +1382,9 @@ func (itr *Iterator) Seek(seek uint64) {
 				itr.c = nil
 				return
 			}
+			itr.key, itr.c = itr.citer.Value()
+			itr.j = -1
+			return
 		}
 		// Set iterator to next value in the Bitmap.
 		itr.j = j
@@ -1387,7 +1392,7 @@ func (itr *Iterator) Seek(seek uint64) {
 		return
 	}
 
-	// If it's a bitmap container then move to index before the value and call next().
+	// If it's a bitmap container then move to index before the value.
 	if itr.key > hb {
 		itr.j = -1
 		return
@@ -1540,14 +1545,14 @@ func (c *Container) count() (n int32) {
 
 // countRange counts the number of bits set between [start, end).
 func (c *Container) countRange(start, end int32) (n int32) {
-	if c == nil {
-		return 0
-	}
 	if roaringParanoia {
 		if start > end {
 			panic(fmt.Sprintf("counting in range but %v > %v", start, end))
 		}
 	}
+	if c == nil {
+		return 0
+	}
 	if c.isArray() {
 		return c.arrayCountRange(start, end)
 	} else if c.isRun() {
diff --git a/roaring/roaring_internal_test.go b/roaring/roaring_internal_test.go
index d064d864f..12dd73d26 100644
--- a/roaring/roaring_internal_test.go
+++ b/roaring/roaring_internal_test.go
@@ -2132,19 +2132,16 @@ func TestIteratorBitmap(t *testing.T) {
 
 	// Test for seeking value not in bitmap, where next container that the iterator should
 	// go to has values with low bits smaller than the low bits of seek.
-	for i := uint64(65536*3 + 2); i < 65536*3+7; i++ {
-		if i != 65536*3+5 {
+	for i := uint64(65536*3 + 2); i < 65536*3+4110; i++ {
+		if i != 65536*3+5 && i != 65536*3+7 {
 			if _, err := b.Add(i); err != nil {
 				t.Fatalf("adding bit: %v", err)
 			}
 		}
 	}
-	for i := uint64(65536*3 + 8); i < 65536*3+4110; i++ {
-		if _, err := b.Add(i); err != nil {
-			t.Fatalf("adding bit: %v", err)
-		}
-	}
 
+	// We expect this to be a bitmap container because more than
+	// 4096 bits have been set, but Optimize() has not been called.
 	if !b.Containers.Get(3).isBitmap() {
 		t.Fatalf("wrong container type")
 	}
@@ -2214,6 +2211,15 @@ func TestIteratorRuns(t *testing.T) {
 		t.Fatalf("iterator did not seek correctly to end of run: %v\n", itr)
 	}
 
+	itr.Seek(1007)
+	if !(itr.key == 1 && itr.j == -1 && itr.k == -1) {
+		t.Fatalf("iterator did not seek correctly to end of run: %v\n", itr)
+	}
+	val, eof = itr.Next()
+	if !(val == 100000 && !eof) {
+		t.Fatalf("iterator did not next correctly across containers: %v, %v", val, itr)
+	}
+
 	itr.Seek(100005)
 	if !(itr.key == 1 && itr.j == 0 && itr.k == 4) {
 		t.Fatalf("iterator did not seek correctly in multiple containers: %v\n", itr)