Index: lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
===================================================================
--- lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -84,13 +84,14 @@
       SmallVector<MVT, 4> Results;
       SmallVector<MVT, 4> Params;
       ComputeSignatureVTs(F, TM, Params, Results);
-      MCSymbolWasm *Sym = cast<MCSymbolWasm>(getSymbol(&F));
+      MCSymbol *Sym = getSymbol(&F);
       getTargetStreamer()->emitIndirectFunctionType(Sym, Params, Results);
 
-      if (F.hasFnAttribute("wasm-import-module")) {
+      MCSymbolWasm *WasmSym = dyn_cast<MCSymbolWasm>(Sym);
+      if (WasmSym && F.hasFnAttribute("wasm-import-module")) {
         StringRef Name = F.getFnAttribute("wasm-import-module")
                              .getValueAsString();
-        getTargetStreamer()->emitImportModule(Sym, Name);
+        getTargetStreamer()->emitImportModule(WasmSym, Name);
       }
     }
   }