diff --git a/src/core/httpcli/parser.c b/src/core/httpcli/parser.c
index f4decda98a97a9c73329abb03965c977f4833a06..7b2a62060c3ca3600154159894ffb0c76170d876 100644
--- a/src/core/httpcli/parser.c
+++ b/src/core/httpcli/parser.c
@@ -177,6 +177,8 @@ static int addbyte(grpc_httpcli_parser *parser, gpr_uint8 byte) {
   }
   gpr_log(GPR_ERROR, "should never reach here");
   abort();
+
+  return 0;
 }
 
 void grpc_httpcli_parser_init(grpc_httpcli_parser *parser) {
diff --git a/src/core/transport/chttp2_transport.c b/src/core/transport/chttp2_transport.c
index 2b15b2a8128cb75d55d7a6c68337617fba7a1ae9..4c0394d46faccf7bd81a2790cda7f0d539c40e10 100644
--- a/src/core/transport/chttp2_transport.c
+++ b/src/core/transport/chttp2_transport.c
@@ -1710,6 +1710,8 @@ static int process_read(transport *t, gpr_slice slice) {
 
   gpr_log(GPR_ERROR, "should never reach here");
   abort();
+
+  return 0;
 }
 
 /* tcp read callback */