diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
index 5f457f0..40b809b 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
@@ -126,7 +126,8 @@
                 break;
               } else {
                 report_fatal_error("Peephole: call to builtin function with "
-                                   "wrong signature, not consuming reg");
+                                   "wrong signature, not consuming reg or "
+                                   "frame index");
               }
             }
           }