diff --git a/src/test/Makefile b/src/test/Makefile
index a3711f4ab..fd0266e1d 100644
--- a/src/test/Makefile
+++ b/src/test/Makefile
@@ -93,7 +93,7 @@ TEST_CFLAGS	 = $(addprefix -I,$(TEST_INCLUDE_DIRS))
 
 $(OBJECT_DIR)/sensors/battery.o : $(USER_DIR)/sensors/battery.c $(USER_DIR)/sensors/battery.h $(GTEST_HEADERS)
 	@mkdir -p $(dir $@)
-	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(TEST_CFLAGS) -c $(USER_DIR)/sensors/battery.c -o $@
+	$(CC) $(CPPFLAGS) $(CXXFLAGS) $(TEST_CFLAGS) -c $(USER_DIR)/sensors/battery.c -o $@
 
 $(OBJECT_DIR)/battery_unittest.o : $(TEST_DIR)/battery_unittest.cc \
                      $(USER_DIR)/sensors/battery.h $(GTEST_HEADERS)
diff --git a/src/test/unit/battery_unittest.cc b/src/test/unit/battery_unittest.cc
index 2263f8b2b..0d30723ec 100644
--- a/src/test/unit/battery_unittest.cc
+++ b/src/test/unit/battery_unittest.cc
@@ -17,7 +17,10 @@
 #include <stdint.h>
 
 #include <limits.h>
-#include "sensors/battery.h"
+
+extern "C" {
+    #include "sensors/battery.h"
+}
 
 #include "unittest_macros.h"
 #include "gtest/gtest.h"
@@ -68,6 +71,8 @@ TEST(BatteryTest, BatteryADCToVoltage)
 
 // STUBS
 
+extern "C" {
+
 uint16_t adcGetChannel(uint8_t channel)
 {
     UNUSED(channel);
@@ -79,3 +84,4 @@ void delay(uint32_t ms)
     UNUSED(ms);
     return;
 }
+}