diff --git a/demo/Makefile.am b/demo/Makefile.am
index 0a79000..7b8e02b 100644
--- a/demo/Makefile.am
+++ b/demo/Makefile.am
@@ -31,7 +31,7 @@ gensource: ${generated_sources}
 
 ${generated_sources}: ${top_srcdir}/demo/rpc_table.py
 	@echo "[libsearpc]: generating rpc header files"
-	python ${top_srcdir}/lib/searpc-codegen.py ${top_srcdir}/demo/rpc_table.py
+	@PYTHON@ ${top_srcdir}/lib/searpc-codegen.py ${top_srcdir}/demo/rpc_table.py
 	@echo "[libsearpc]: done"
 
 clean-local:
diff --git a/lib/searpc-codegen.py b/lib/searpc-codegen.py
index 35cc859..be0e491 100644
--- a/lib/searpc-codegen.py
+++ b/lib/searpc-codegen.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 
 """
 Generate function define macros.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 5aa52e0..686d0f1 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -23,7 +23,7 @@ gensource: ${generated_sources}
 
 ${generated_sources}: $(top_srcdir)/tests/rpc_table.py
 	@echo "[libsearpc]: generating rpc header files"
-	python ${top_srcdir}/lib/searpc-codegen.py $(top_srcdir)/tests/rpc_table.py
+	@PYTHON@ ${top_srcdir}/lib/searpc-codegen.py $(top_srcdir)/tests/rpc_table.py
 	@echo "[libsearpc]: done"
 
 clean-local: