diff --git a/src/Convert/SizeCast.hs b/src/Convert/SizeCast.hs
index 98cd5c1..ec4cdc1 100644
--- a/src/Convert/SizeCast.hs
+++ b/src/Convert/SizeCast.hs
@@ -70,6 +70,12 @@ traverseExprM =
                 _ -> convertCastM (Number s) (Number n)
         convertExprM (orig @ (Cast (Right DimsFn{}) _)) =
             return orig
+        convertExprM (Cast (Right (Ident x)) e) = do
+            typeMap <- get
+            -- can't convert this cast yet because x could be a typename
+            if Map.notMember x typeMap
+                then return $ Cast (Right $ Ident x) e
+                else convertCastM (Ident x) e
         convertExprM (Cast (Right s) e) =
             convertCastM s e
         convertExprM (Cast (Left (IntegerVector _ Signed rs)) e) =
diff --git a/test/basic/typename_cast.sv b/test/basic/typename_cast.sv
new file mode 100644
index 0000000..4156a60
--- /dev/null
+++ b/test/basic/typename_cast.sv
@@ -0,0 +1,6 @@
+module Example;
+    parameter type T = logic [3:0];
+    T v = T'('1);
+    initial #1 $display("%b", v);
+endmodule
+module top; Example example(); endmodule
diff --git a/test/basic/typename_cast.v b/test/basic/typename_cast.v
new file mode 100644
index 0000000..b5c9505
--- /dev/null
+++ b/test/basic/typename_cast.v
@@ -0,0 +1,5 @@
+module Example;
+    wire [3:0] v = 4'b1111;
+    initial #1 $display("%b", v);
+endmodule
+module top; Example example(); endmodule