diff --git a/hidtest/Makefile.am b/hidtest/Makefile.am
index d278644..5f52c3f 100644
--- a/hidtest/Makefile.am
+++ b/hidtest/Makefile.am
@@ -4,17 +4,17 @@ AM_CPPFLAGS = -I$(top_srcdir)/hidapi/
 if OS_LINUX
 noinst_PROGRAMS = hidtest-libusb hidtest-hidraw
 
-hidtest_hidraw_SOURCES = hidtest.cpp
+hidtest_hidraw_SOURCES = hidtest.c
 hidtest_hidraw_LDADD = $(top_builddir)/linux/libhidapi-hidraw.la
 
-hidtest_libusb_SOURCES = hidtest.cpp
+hidtest_libusb_SOURCES = hidtest.c
 hidtest_libusb_LDADD = $(top_builddir)/libusb/libhidapi-libusb.la
 else
 
 # Other OS's
 noinst_PROGRAMS = hidtest
 
-hidtest_SOURCES = hidtest.cpp
+hidtest_SOURCES = hidtest.c
 hidtest_LDADD = $(top_builddir)/$(backend)/libhidapi.la
 
 endif
diff --git a/hidtest/hidtest.cpp b/hidtest/hidtest.c
similarity index 100%
rename from hidtest/hidtest.cpp
rename to hidtest/hidtest.c
diff --git a/windows/hidtest.vcproj b/windows/hidtest.vcproj
index db64f96..8cc435f 100644
--- a/windows/hidtest.vcproj
+++ b/windows/hidtest.vcproj
@@ -174,7 +174,7 @@
 			UniqueIdentifier="{4FC737F1-C7A5-4376-A066-2A32D752A2FF}"
 			>
 			<File
-				RelativePath="..\hidtest\hidtest.cpp"
+				RelativePath="..\hidtest\hidtest.c"
 				>
 			</File>
 		</Filter>