diff --git a/ivtest/ivltests/task_nonansi_fail1.v b/ivtest/ivltests/task_nonansi_fail1.v
new file mode 100644
index 000000000..f81ee6e92
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail1.v
@@ -0,0 +1,15 @@
+// Check that declaring multiple task non-ANSI ports with the same name is an
+// error. Even if they both have an implicit type.
+
+module test;
+
+  task t;
+    input x;
+    input x;
+    $display("FAILED");
+  endtask
+
+  reg y;
+  initial t(y, y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail10.v b/ivtest/ivltests/task_nonansi_fail10.v
new file mode 100644
index 000000000..10705a602
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail10.v
@@ -0,0 +1,17 @@
+// Check that declaring two non-ANSI task ports with an implicit type and the
+// same name is an error. Even if the signal was previously declared as an
+// variable.
+
+module test;
+
+  task t;
+    integer x;
+    input x;
+    input x;
+    $display("FAILED");
+  endtask
+
+  integer y;
+  initial t(y, y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail11.v b/ivtest/ivltests/task_nonansi_fail11.v
new file mode 100644
index 000000000..82d4b2285
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail11.v
@@ -0,0 +1,15 @@
+// Check that declaring two non-ANSI output task ports with an explicit type is
+// an error. Even if the types are the same.
+
+module test;
+
+  task t;
+    input integer x;
+    input integer x;
+    $display("FAILED");
+  endtask
+
+  integer y;
+  initial t(y, y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail2.v b/ivtest/ivltests/task_nonansi_fail2.v
new file mode 100644
index 000000000..9e4f07537
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail2.v
@@ -0,0 +1,16 @@
+// Check that declaring a variable multiple times for a signal that was
+// previously declared as a non-ANSI task input port is an error.
+
+module test;
+
+  task t;
+    input x;
+    reg x;
+    reg x;
+    $display("FAILED");
+  endtask
+
+  reg y;
+  initial t(y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail3.v b/ivtest/ivltests/task_nonansi_fail3.v
new file mode 100644
index 000000000..584b2dfd3
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail3.v
@@ -0,0 +1,16 @@
+// Check that declaring a variable multiple times for a signal that was
+// previously declared as a non-ANSI task output port is an error.
+
+module test;
+
+  task t;
+    output x;
+    reg x;
+    reg x;
+    $display("FAILED");
+  endtask
+
+  reg y;
+  initial t(y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail4.v b/ivtest/ivltests/task_nonansi_fail4.v
new file mode 100644
index 000000000..c5d3249c8
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail4.v
@@ -0,0 +1,16 @@
+// Check that declaring an integer typed non-ANSI task port for signal that was
+// previously declared as a variable is an error. Even if the types for both
+// declarations are the same.
+
+module test;
+
+  task t;
+    integer x;
+    input integer x;
+    $display("FAILED");
+  endtask
+
+  integer y;
+  initial t(y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail5.v b/ivtest/ivltests/task_nonansi_fail5.v
new file mode 100644
index 000000000..e1b3f2d8e
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail5.v
@@ -0,0 +1,15 @@
+// Check that declaring an integer typed variabe for a signal that was
+// previously declared as a non-ANSI task port is an error. Even if the types
+// for both declarations are the same.
+
+module test;
+
+  task t;
+    input integer x;
+    integer x;
+    $display("FAILED");
+  endtask
+
+  initial t();
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail6.v b/ivtest/ivltests/task_nonansi_fail6.v
new file mode 100644
index 000000000..7b0c09ada
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail6.v
@@ -0,0 +1,16 @@
+// Check that declaring a real typed variable for a signal that was previously
+// declared as a non-ANSI task port is an error. Even if the types for both
+// declarations are the same.
+
+module test;
+
+  task t;
+    output real x;
+    real x;
+    $display("FAILED");
+  endtask
+
+  real y;
+  initial t(y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail7.v b/ivtest/ivltests/task_nonansi_fail7.v
new file mode 100644
index 000000000..5d994273d
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail7.v
@@ -0,0 +1,16 @@
+// Check that declaring a real typed non-ANSI task port for signal that was
+// previously declared as a variable is an error. Even if the types for both
+// declarations are the same.
+
+module test;
+
+  task t;
+    real x;
+    output real x;
+    $display("FAILED");
+  endtask
+
+  real y;
+  initial t(y);
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail8.v b/ivtest/ivltests/task_nonansi_fail8.v
new file mode 100644
index 000000000..6adf2e2cd
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail8.v
@@ -0,0 +1,14 @@
+// Check that declaring an integer typed variable for a signal that was previously
+// declared as a real typed non-ANSI task port is an error.
+
+module test;
+
+  task t;
+    output real x;
+    integer x;
+    $display("FAILED");
+  endtask
+
+  initial t();
+
+endmodule
diff --git a/ivtest/ivltests/task_nonansi_fail9.v b/ivtest/ivltests/task_nonansi_fail9.v
new file mode 100644
index 000000000..17ad486d1
--- /dev/null
+++ b/ivtest/ivltests/task_nonansi_fail9.v
@@ -0,0 +1,15 @@
+// Check that declaring a non-ANSI task port with an explicit type for a signal
+// that was previously declared real variable is an error.
+
+module test;
+
+  task t;
+    real x;
+    output integer x;
+    $display("FAILED");
+  endtask
+
+  real y;
+  initial t(y);
+
+endmodule
diff --git a/ivtest/regress-vlg.list b/ivtest/regress-vlg.list
index 15c51ccb0..2b8274d21 100644
--- a/ivtest/regress-vlg.list
+++ b/ivtest/regress-vlg.list
@@ -1652,6 +1652,17 @@ task_inpad		normal			ivltests # Validates input of task should pad w/ 0
 task_iotypes		normal			ivltests # task ports with types.
 task_iotypes2		normal			ivltests # task ports with types.
 task_mem		normal			ivltests
+task_nonansi_fail1	CE			ivltests
+task_nonansi_fail2	CE			ivltests
+task_nonansi_fail3	CE			ivltests
+task_nonansi_fail4	CE			ivltests
+task_nonansi_fail5	CE			ivltests
+task_nonansi_fail6	CE			ivltests
+task_nonansi_fail7	CE			ivltests
+task_nonansi_fail8	CE			ivltests
+task_nonansi_fail9	CE			ivltests
+task_nonansi_fail10	CE			ivltests
+task_nonansi_fail11	CE			ivltests
 task_nonansi_integer1	normal			ivltests
 task_nonansi_integer2	normal			ivltests
 task_nonansi_integer_fail CE			ivltests