diff --git a/test/packet_inject/CMakeLists.txt b/test/packet_inject/CMakeLists.txt
index 3bfb3c2..404fe3e 100644
--- a/test/packet_inject/CMakeLists.txt
+++ b/test/packet_inject/CMakeLists.txt
@@ -1,5 +1,5 @@
 # build libpacket_inject.so
-add_library(packet_inject SHARED packet_inject.cpp)
+add_library(packet_inject SHARED packet_inject.c)
 target_link_libraries(packet_inject toml)
 target_include_directories(packet_inject PUBLIC ${CMAKE_SOURCE_DIR}/include/)
 set_target_properties(packet_inject PROPERTIES LINK_FLAGS "-Wl,--version-script=${CMAKE_CURRENT_LIST_DIR}/version.map")
diff --git a/test/packet_inject/packet_inject.cpp b/test/packet_inject/packet_inject.c
similarity index 100%
rename from test/packet_inject/packet_inject.cpp
rename to test/packet_inject/packet_inject.c