diff --git a/sv-parser-pp/testcases/expected/undefineall.sv b/sv-parser-pp/testcases/expected/undefineall.sv
new file mode 100644
index 0000000..c711d39
--- /dev/null
+++ b/sv-parser-pp/testcases/expected/undefineall.sv
@@ -0,0 +1,29 @@
+// IEEE1800-2017 Clause 22.5.2
+// The directive `undef shall undefine the specified text macro if previously
+// defined by a `define compiler directive within the compilation unit. An
+// attempt to undefine a text macro that was not previously defined using a
+// `define compiler directive can issue a warning.
+`undef FOO
+`undef FOO// Comment
+`undef FOO // Comment
+
+`define FOO foo
+`define BAR bar
+// AAA
+// This block SHOULD be emitted from the preprocessor.
+
+
+// BBB
+// This block SHOULD be emitted from the preprocessor.
+
+
+
+`undefineall
+
+// CCC
+// This block SHOULD be emitted from the preprocessor.
+
+
+// DDD
+// This block SHOULD be emitted from the preprocessor.
+
diff --git a/sv-parser-pp/testcases/undefineall.sv b/sv-parser-pp/testcases/undefineall.sv
new file mode 100644
index 0000000..734fb4a
--- /dev/null
+++ b/sv-parser-pp/testcases/undefineall.sv
@@ -0,0 +1,45 @@
+// IEEE1800-2017 Clause 22.5.3
+// The directive `undefineall directive shall undefine all text macros
+// previously defined by `define compiler directives within the compilation
+// unit. This directive takes no argument and may appear anywhere in the source
+// description.
+`undefineall
+`undefineall// Comment
+`undefineall // Comment
+
+`define FOO foo
+`define BAR bar
+`ifdef FOO
+// AAA
+// This block SHOULD be emitted from the preprocessor.
+`endif
+`ifndef FOO
+// AAA
+// This block should NOT be emitted from the preprocessor.
+`endif
+`ifdef BAR
+// BBB
+// This block SHOULD be emitted from the preprocessor.
+`endif
+`ifndef BAR
+// BBB
+// This block should NOT be emitted from the preprocessor.
+`endif
+
+`undefineall
+`ifdef FOO
+// CCC
+// This block should NOT be emitted from the preprocessor.
+`endif
+`ifndef FOO
+// CCC
+// This block SHOULD be emitted from the preprocessor.
+`endif
+`ifdef BAR
+// DDD
+// This block should NOT be emitted from the preprocessor.
+`endif
+`ifndef BAR
+// DDD
+// This block SHOULD be emitted from the preprocessor.
+`endif