diff --git a/editor/fn.go b/editor/fn.go
index 9ab445f..c8a85a6 100644
--- a/editor/fn.go
+++ b/editor/fn.go
@@ -44,11 +44,11 @@ func isCtrl(char rune) bool {
 
 // Return the input code of a Ctrl-key chord.
 func ctrl(char rune) rune {
-	ch := char & 0x1f
-
-	if !isCtrl(ch) {
+	if !isAscii(char) {
 		return 0
 	}
 
+	ch := char & 0x1f
+
 	return ch
 }
\ No newline at end of file
diff --git a/editor/fn_test.go b/editor/fn_test.go
index 943d508..bf01b6e 100644
--- a/editor/fn_test.go
+++ b/editor/fn_test.go
@@ -41,6 +41,27 @@ func TestIsCtrl(t *testing.T) {
 	}
 }
 
+type ctrlTest struct {
+	arg1, expected rune
+}
+
+var ctrlTests = []ctrlTest {
+	{'A', '\x01'},
+	{'B', '\x02'},
+	{'Z', '\x1a'},
+	{'#', 3},
+	{'┻', 0},
+	{'😿', 0},
+}
+
+func TestCtrl(t *testing.T) {
+	for _, test := range ctrlTests {
+		if output := ctrl(test.arg1); output != test.expected {
+			t.Errorf("Output %v not equal to expected %v for input %q", output, test.expected, test.arg1)
+		}
+	}
+}
+
 func TestTruncateString(t *testing.T) {
 	firstString := "abcdefghijklmnopqrstuvwxyz"
 	truncated := truncateString(firstString, 13)