diff --git a/src/Convert/PortDecl.hs b/src/Convert/PortDecl.hs
index 0561f10..9e3a808 100644
--- a/src/Convert/PortDecl.hs
+++ b/src/Convert/PortDecl.hs
@@ -28,11 +28,20 @@ traverseDescription :: Description -> Description
 traverseDescription (Part attrs extern kw liftetime name ports items) =
     Part attrs extern kw liftetime name ports items'
     where items' = convertPorts name ports items
+traverseDescription (PackageItem item) =
+    PackageItem $ convertPackageItem item
 traverseDescription other = other
 
+convertPackageItem :: PackageItem -> PackageItem
+convertPackageItem (Function l t x decls stmts) =
+   Function l t x (convertTFDecls decls) stmts
+convertPackageItem (Task l x decls stmts) =
+   Task l x (convertTFDecls decls) stmts
+convertPackageItem other = other
+
 convertPorts :: Identifier -> [Identifier] -> [ModuleItem] -> [ModuleItem]
 convertPorts name ports items
-    | not (null extraPorts) =
+    | not (null name) && not (null extraPorts) =
         error $ "declared ports " ++ intercalate ", " extraPorts
             ++ " are not in the port list of " ++ name
     | otherwise =
@@ -48,6 +57,8 @@ convertPorts name ports items
             | Variable d _ x _ e <- decl = rewrite decl (combineIdent x) d x e
             | Net  d _ _ _ x _ e <- decl = rewrite decl (combineIdent x) d x e
             | otherwise = MIPackageItem $ Decl decl
+        traverseItem (MIPackageItem item) =
+            MIPackageItem $ convertPackageItem item
         traverseItem other = other
 
         -- produce the combined declaration for a port, if it has one
@@ -57,6 +68,17 @@ convertPorts name ports items
             dataDecl <- lookup x dataDecls
             Just $ combineDecls portDecl dataDecl
 
+-- wrapper for convertPorts enabling its application to task or function decls
+convertTFDecls :: [Decl] -> [Decl]
+convertTFDecls =
+    map unwrap . convertPorts "" [] . map wrap
+    where
+        wrap :: Decl -> ModuleItem
+        wrap = MIPackageItem . Decl
+        unwrap :: ModuleItem -> Decl
+        unwrap item = decl
+            where MIPackageItem (Decl decl) = item
+
 -- given helpfully extracted information, update the given declaration
 rewrite :: Decl -> Maybe Decl -> Direction -> Identifier -> Expr -> ModuleItem
 -- implicitly-typed ports default to `logic` in SystemVerilog
diff --git a/test/core/non_ansi_port_decl_tf.sv b/test/core/non_ansi_port_decl_tf.sv
new file mode 100644
index 0000000..b8842c1
--- /dev/null
+++ b/test/core/non_ansi_port_decl_tf.sv
@@ -0,0 +1,22 @@
+function automatic [4:0] f;
+    input signed [3:0] x;
+    reg [3:0] x;
+    var type(x) y;
+    y = x;
+    f = y;
+endfunction
+module top;
+    task t;
+        input signed [3:0] x;
+        reg [3:0] x;
+        var type(x) y;
+        reg [4:0] z;
+        y = x;
+        z = y;
+        $display("t(%b) -> %b", x, z);
+    endtask
+    localparam [3:0] X = 4'b1011;
+    localparam [4:0] Y = f(X);
+    initial $display("f(%b) -> %b", X, Y);
+    initial t(X);
+endmodule
diff --git a/test/core/non_ansi_port_decl_tf.v b/test/core/non_ansi_port_decl_tf.v
new file mode 100644
index 0000000..0f6998c
--- /dev/null
+++ b/test/core/non_ansi_port_decl_tf.v
@@ -0,0 +1,18 @@
+module top;
+    function automatic [4:0] f;
+        input reg signed [3:0] x;
+        f = x;
+    endfunction
+    task t;
+        input signed [3:0] x;
+        reg [4:0] z;
+        begin
+            z = x;
+            $display("t(%b) -> %b", x, z);
+        end
+    endtask
+    localparam [3:0] X = 4'b1011;
+    localparam [4:0] Y = f(X);
+    initial $display("f(%b) -> %b", X, Y);
+    initial t(X);
+endmodule