diff --git a/src/Convert/SystemTasks.hs b/src/Convert/SystemTasks.hs
index 269d3c9..73c11e0 100644
--- a/src/Convert/SystemTasks.hs
+++ b/src/Convert/SystemTasks.hs
@@ -10,7 +10,39 @@ import Convert.Traverse
 import Language.SystemVerilog.AST
 
 convert :: [AST] -> [AST]
-convert = map $ traverseDescriptions $ traverseModuleItems convertModuleItem
+convert = map $ traverseDescriptions traverseDescription
+
+elaborationFatalIdent :: Identifier
+elaborationFatalIdent = "_sv2v_elaboration_fatal"
+
+elaborationFatalCancelCode :: Expr
+elaborationFatalCancelCode = RawNum (-1)
+
+elaborationFatalDecl :: ModuleItem
+elaborationFatalDecl = MIPackageItem $ Decl $ Variable Local t elaborationFatalIdent [] elaborationFatalCancelCode
+    where t = IntegerAtom TInteger Unspecified
+
+elaborationFatalCheck :: ModuleItem
+elaborationFatalCheck = Initial (Block Seq "" [] [
+        zeroDelay,
+        If NoCheck checkCancelCode finishCall Null
+    ]) where
+        zeroDelay = Timing (Delay (RawNum 0)) Null
+        checkCancelCode = BinOpA Ne [] (Ident elaborationFatalIdent) elaborationFatalCancelCode
+        finishCall = Subroutine (Ident "$finish") (Args [(Ident elaborationFatalIdent)] [])
+
+traverseDescription :: Description -> Description
+traverseDescription (Part att ext kw lif name pts items) =
+    traverseModuleItems convertModuleItem $
+    Part att ext kw lif name pts $
+    if hasElaborationFatal
+        then elaborationFatalDecl : items ++ [elaborationFatalCheck]
+        else items
+    where
+        hasElaborationFatal = any isElabTaskFatal items
+        isElabTaskFatal (ElabTask SeverityFatal _) = True
+        isElabTaskFatal _ = False
+traverseDescription description = traverseModuleItems convertModuleItem description
 
 convertModuleItem :: ModuleItem -> ModuleItem
 
diff --git a/src/Language/SystemVerilog/AST/Number.hs b/src/Language/SystemVerilog/AST/Number.hs
index 6744590..ebaecb6 100644
--- a/src/Language/SystemVerilog/AST/Number.hs
+++ b/src/Language/SystemVerilog/AST/Number.hs
@@ -322,7 +322,7 @@ numberBitLength (Based size _ _ _ _) =
         then max 32 $ negate size
         else size
 
--- get whether or not a number is signed
+-- get whether or not a number is sized
 numberIsSized :: Number -> Bool
 numberIsSized UnbasedUnsized{} = False
 numberIsSized (Decimal size _ _) = size > 0
@@ -359,9 +359,7 @@ instance Show Number where
     show (UnbasedUnsized bit) =
         '\'' : show bit
     show (Decimal (-32) True value) =
-        if value < 0
-            then error $ "illegal decimal: " ++ show value
-            else show value
+        show value
     show (Decimal size signed value) =
         if size == 0
             then error $ "illegal decimal literal: "