diff --git a/Makefile b/Makefile
index 2ff93989dd..68f6faffa1 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,7 @@ CLIENT_TEST_DIR ?= build_test
 
 # Python packages to install only from source (not from binary wheels)
 # Comma separated list
-SRC_ONLY_PKGS ?= cffi
+SRC_ONLY_PKGS ?= cffi,pycparser
 
 # Determine appropriate shasum command
 UNAME_S := $(shell uname -s)