diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 358fad3..60943f5 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -1085,6 +1085,6 @@
 
   # TODO (mxyan): Instead of this hack, add include path "third_party" to C core's include path?
   s.prepare_command = <<-END_OF_COMMAND
-    find src/core/ -type f -exec sed -E -i '.back' 's;#include "third_party/nanopb/(.*)";#include <nanopb/\\1>;g' {} \\\;
+    find src/core/ -type f -exec sed -E -i'.back' 's;#include "third_party/nanopb/(.*)";#include <nanopb/\\1>;g' {} \\\;
   END_OF_COMMAND
 end