diff --git a/lexer/ascii_control_character.invalid.mj b/lexer/ascii_control_character.invalid.mj
new file mode 100644
index 0000000000000000000000000000000000000000..7d9b6628123679ab0fb8679930df043da860af4d
--- /dev/null
+++ b/lexer/ascii_control_character.invalid.mj
@@ -0,0 +1 @@
+/* Now comes ASCII \x1b (ESC) */ 
diff --git a/lexer/invalid_utf8.invalid.mj b/lexer/invalid_utf8.invalid.mj
new file mode 100644
index 0000000000000000000000000000000000000000..38cdfc771fed2f6b7b26c38c144ae522c501dc3d
--- /dev/null
+++ b/lexer/invalid_utf8.invalid.mj
@@ -0,0 +1,11 @@
+/* Extracted from Markus Kuhn <http://www.cl.cam.ac.uk/~mgk25/> - 2015-08-28 - CC BY 4.0 */
+
+/* First continuation byte 0x80 */ €
+/* Last continuation byte 0xbf */ ¿
+
+/* 2 continuation bytes */ €¿
+/* 3 continuation bytes */ €¿€
+/* 4 continuation bytes */ €¿€¿
+/* 5 continuation bytes */ €¿€¿€
+/* 6 continuation bytes */ €¿€¿€¿
+/* 7 continuation bytes */ €¿€¿€¿€
diff --git a/lexer/overlong_ascii.invalid.mj b/lexer/overlong_ascii.invalid.mj
new file mode 100644
index 0000000000000000000000000000000000000000..33d6ad31038d5bce5845dac5d98162ed10df6101
--- /dev/null
+++ b/lexer/overlong_ascii.invalid.mj
@@ -0,0 +1,8 @@
+/* Extracted from Markus Kuhn <http://www.cl.cam.ac.uk/~mgk25/> - 2015-08-28 - CC BY 4.0 */
+
+/* Overlong ASCII characters */
+/* U+002F = c0 af             */ À¯
+/* U+002F = e0 80 af          */ à€¯
+/* U+002F = f0 80 80 af       */ ð€€¯
+/* U+002F = f8 80 80 80 af    */ ø€€€¯
+/* U+002F = fc 80 80 80 80 af */ ü€€€€¯
diff --git a/lexer/valid_utf8.invalid.mj b/lexer/valid_utf8.invalid.mj
new file mode 100644
index 0000000000000000000000000000000000000000..776360ae0351d9200e77d7852b5a58029340adcd
--- /dev/null
+++ b/lexer/valid_utf8.invalid.mj
@@ -0,0 +1 @@
+public static void μαιν(String[] args) {}
diff --git a/lexer/weird_whitespace.mj b/lexer/weird_whitespace.mj
new file mode 100644
index 0000000000000000000000000000000000000000..4f83a3943658085236adb63b375caba094a6e162
--- /dev/null
+++ b/lexer/weird_whitespace.mj
@@ -0,0 +1,2 @@
+/* Now comes ASCII \t\n\v\f (horizontal tab, new line, vertial tab, form feed) */ 	
+
\ No newline at end of file
diff --git a/lexer/weird_whitespace.mj.out b/lexer/weird_whitespace.mj.out
new file mode 100644
index 0000000000000000000000000000000000000000..1a2b1dc142b40bd859036d3dac387b1b93663d06
--- /dev/null
+++ b/lexer/weird_whitespace.mj.out
@@ -0,0 +1 @@
+EOF