diff --git a/cue/builtin_test.go b/cue/builtin_test.go
index 573da3f..73d3fd7 100644
--- a/cue/builtin_test.go
+++ b/cue/builtin_test.go
@@ -304,8 +304,23 @@
 		test("strings", `strings.MinRunes(1) & "e"`),
 		`"e"`,
 	}, {
-		test("strings", `strings.MinRunes(0) & "e"`),
-		`_|_(invalid value "e" (does not satisfy strings.MinRunes(0)))`,
+		test("strings", `strings.MaxRunes(0) & "e"`),
+		`_|_(invalid value "e" (does not satisfy strings.MaxRunes(0)))`,
+	}, {
+		test("strings", `strings.MaxRunes(0) & ""`),
+		`""`,
+	}, {
+		test("strings", `strings.MinRunes(3) & "hello"`),
+		`"hello"`,
+	}, {
+		test("strings", `strings.MaxRunes(10) & "hello"`),
+		`"hello"`,
+	}, {
+		test("strings", `strings.MaxRunes(3) & "hello"`),
+		`_|_(invalid value "hello" (does not satisfy strings.MaxRunes(3)))`,
+	}, {
+		test("strings", `strings.MinRunes(10) & "hello"`),
+		`_|_(invalid value "hello" (does not satisfy strings.MinRunes(10)))`,
 	}, {
 		test("struct", `struct.MinFields(0) & ""`),
 		`_|_(conflicting values MinFields (0) and "" (mismatched types struct and string))`,
diff --git a/cue/builtins.go b/cue/builtins.go
index 33262ef..bdb686b 100644
--- a/cue/builtins.go
+++ b/cue/builtins.go
@@ -2025,10 +2025,11 @@
 			Params: []kind{stringKind, intKind},
 			Result: boolKind,
 			Func: func(c *callCtxt) {
-				s, max := c.string(0), c.int(1)
+				s, min := c.string(0), c.int(1)
 				c.ret = func() interface{} {
 
-					return len([]rune(s)) <= max
+					fmt.Println(len([]rune(s)))
+					return len([]rune(s)) >= min
 				}()
 			},
 		}, {
diff --git a/pkg/strings/manual.go b/pkg/strings/manual.go
index de3436d..508466d 100644
--- a/pkg/strings/manual.go
+++ b/pkg/strings/manual.go
@@ -56,11 +56,11 @@
 // MinRunes reports whether the number of runes (Unicode codepoints) in a string
 // is at least a certain minimum. MinRunes can be used a a field constraint to
 // except all strings for which this property holds.
-func MinRunes(s string, max int) bool {
+func MinRunes(s string, min int) bool {
 	// TODO: CUE strings cannot be invalid UTF-8. In case this changes, we need
 	// to use the following conversion to count properly:
 	// s, _ = unicodeenc.UTF8.NewDecoder().String(s)
-	return len([]rune(s)) <= max
+	return len([]rune(s)) >= min
 }
 
 // MaxRunes reports whether the number of runes (Unicode codepoints) in a string