diff --git a/contains_test.go b/contains_test.go
index d67ad61..90cd9e6 100644
--- a/contains_test.go
+++ b/contains_test.go
@@ -12,3 +12,8 @@ func TestContains(t *testing.T) {
 	nums := []int{1, 3, 5, 7, 9}
 	assert.True(t, u.Contains(nums, 5))
 }
+
+func TestNotContains(t *testing.T) {
+	nums := []int{1, 3, 5, 7, 9}
+	assert.False(t, u.Contains(nums, 15))
+}
diff --git a/every_test.go b/every_test.go
index 4f5c371..2a6474d 100644
--- a/every_test.go
+++ b/every_test.go
@@ -13,3 +13,9 @@ func TestEvery(t *testing.T) {
 	isOdd := func(n int) bool { return n%2 != 0 }
 	assert.True(t, u.Every(nums, isOdd))
 }
+
+func TestNotEvery(t *testing.T) {
+	nums := []int{1, 3, 5, 7, 9, 10}
+	isOdd := func(n int) bool { return n%2 != 0 }
+	assert.False(t, u.Every(nums, isOdd))
+}
diff --git a/min_test.go b/min_test.go
index ab66847..2b4f6cc 100644
--- a/min_test.go
+++ b/min_test.go
@@ -9,7 +9,7 @@ import (
 )
 
 func TestMin(t *testing.T) {
-	nums := []int{1, 9, 2, 8, 3, 7, 4, 6, 5}
+	nums := []int{9, 2, 1, 8, 3, 7, 4, 6, 5}
 	want := 1
 	assert.Equal(t, want, u.Min(nums))
 }
diff --git a/some_test.go b/some_test.go
index 1428ef6..05d4395 100644
--- a/some_test.go
+++ b/some_test.go
@@ -10,7 +10,14 @@ import (
 
 func TestSome(t *testing.T) {
 	nums := []int{1, 2, 4, 6, 8}
-	isEven := func(n int) bool { return n%2 == 0 }
+	isOdd := func(n int) bool { return n%2 != 0 }
 
-	assert.True(t, u.Some(nums, isEven))
+	assert.True(t, u.Some(nums, isOdd))
+}
+
+func TestNotSome(t *testing.T) {
+	nums := []int{2, 4, 6, 8}
+	isOdd := func(n int) bool { return n%2 != 0 }
+
+	assert.False(t, u.Some(nums, isOdd))
 }