diff --git a/sw/airborne/math/Makefile b/sw/airborne/math/Makefile
index 11cba79adb..3d7873a2c7 100644
--- a/sw/airborne/math/Makefile
+++ b/sw/airborne/math/Makefile
@@ -31,7 +31,8 @@ all:
 	@cat README
 
 shared_lib: $(OBJ)
-	$(CC) -shared -o $(BUILDDIR)/$(LIBNAME).so $(OBJ) -lm
+	@echo CREATE shared $(LIBNAME)
+	$(Q)$(CC) -shared -o $(BUILDDIR)/$(LIBNAME).so $(OBJ) -lm
 
 install_shared_lib: shared_lib
 	test -d $(LIB_INSTALLDIR) || mkdir -p $(LIB_INSTALLDIR)
@@ -43,8 +44,8 @@ install_shared_lib: shared_lib
 	sed -e 's#PREFIX#$(PREFIX)#g' $(PKGCONFIG_FILE).in > $(PKGCONFIG_INSTALLDIR)/$(PKGCONFIG_FILE)
 
 $(BUILDDIR)/%.o: %.c
-	test -d $(BUILDDIR) || mkdir -p $(BUILDDIR)
-	$(CC) -c $< $(CFLAGS) $(INCLUDES) -o $@
+	$(Q)test -d $(BUILDDIR) || mkdir -p $(BUILDDIR)
+	$(Q)$(CC) -c $< $(CFLAGS) $(INCLUDES) -o $@
 
 clean:
 	$(Q)rm -f $(BUILDDIR)/*.o $(BUILDDIR)/$(LIBNAME).so
diff --git a/tests/math/.gitignore b/tests/math/.gitignore
index c2120bd679..abad43aa66 100644
--- a/tests/math/.gitignore
+++ b/tests/math/.gitignore
@@ -1,2 +1,3 @@
 test_pprz_math.run
 test_pprz_geodetic.run
+test_state_interface.run
diff --git a/tests/math/Makefile b/tests/math/Makefile
index f5edbc0526..26d0fdc3a7 100644
--- a/tests/math/Makefile
+++ b/tests/math/Makefile
@@ -36,11 +36,16 @@ MATHLIB_PATH=$(PAPARAZZI_SRC)/var/build/math
 
 #####################################################
 # If you add more test files you add their names here
-TESTS = test_pprz_math.run test_pprz_geodetic.run
+TESTS = test_pprz_math.run test_pprz_geodetic.run test_state_interface.run
 
 ###################################################
 # You should not need to touch the rest of the file
 
+TEST_VERBOSE ?= 0
+ifneq ($(TEST_VERBOSE), 0)
+VERBOSE = --verbose
+endif
+
 all: test
 
 math_shlib:
@@ -49,12 +54,14 @@ math_shlib:
 build_tests: math_shlib $(TESTS)
 
 test: build_tests
-	$(Q)for i in $(TESTS); do \
-	LD_LIBRARY_PATH=$(MATHLIB_PATH):$LD_LIBRARY_PATH ./$$i;	\
-	done
+	LD_LIBRARY_PATH=$(MATHLIB_PATH):$LD_LIBRARY_PATH prove $(VERBOSE) --exec '' ./*.run
 
-%.run: %.c
-	$(CC) -L$(MATHLIB_PATH) -I$(PAPARAZZI_SRC)/sw/airborne -I$(PAPARAZZI_SRC)/sw/include $(USER_CFLAGS) tap.c $< -lpprzmath -o $@
+# test_state_interface also depends on state.c
+test_state_interface.run: $(PAPARAZZI_SRC)/sw/airborne/state.c
+
+%.run: %.c | math_shlib
+	@echo BUILD $@
+	$(Q)$(CC) -L$(MATHLIB_PATH) -I$(PAPARAZZI_SRC)/sw/airborne -I$(PAPARAZZI_SRC)/sw/include $(USER_CFLAGS) tap.c $^ -lpprzmath -o $@
 
 clean:
 	$(Q)rm -f $(MATHLIB_PATH)/*.o $(MATHLIB_PATH)/libpprzmath.so
diff --git a/tests/math/test_state_interface.c b/tests/math/test_state_interface.c
new file mode 100644
index 0000000000..833f6221f9
--- /dev/null
+++ b/tests/math/test_state_interface.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2014 Felix Ruess <felix.ruess@gmail.com>
+ *
+ * This file is part of paparazzi.
+ *
+ * paparazzi is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * paparazzi is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with paparazzi; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file test_state_interface.c
+ * @brief Tests for Paparazzi state interface.
+ *
+ * Which heavily uses the math libary.
+ *
+ * Using libtap to create a TAP (TestAnythingProtocol) producer:
+ * https://github.com/zorgnax/libtap
+ *
+ */
+
+#include "tap.h"
+#include "state.h"
+#include "math/pprz_geodetic_double.h"
+
+static void test_pos_lla_i(void)
+{
+  struct LlaCoor_d lla_ref = {.lat=0.749999999392454875,
+                              .lon=0.019999999054505127,
+                              .alt=180.0};
+  note("LLA reference: lat: %.10f deg, lon: %.10f deg, alt %.4f m",
+       DegOfRad(lla_ref.lat), DegOfRad(lla_ref.lon), lla_ref.alt);
+
+  struct LlaCoor_i lla_ref_i;
+  LLA_BFP_OF_REAL(lla_ref_i, lla_ref);
+
+  struct EcefCoor_d ecef_ref;
+  ecef_of_lla_d(&ecef_ref, &lla_ref);
+  note("ECEF reference: x: %.4f m, y: %.4f m, z: %.4f m",
+       ecef_ref.x, ecef_ref.y, ecef_ref.z);
+
+  /* calc lla_i from ecef_f */
+  struct EcefCoor_f ecef_f;
+  VECT3_COPY(ecef_f, ecef_ref);
+  stateSetPositionEcef_f(&ecef_f);
+
+  struct LlaCoor_i *lla_result;
+  lla_result = stateGetPositionLla_i();
+
+  /* compare LLA result with reference (directly convered from double) */
+  int32_t lat_err = abs(lla_result->lat - lla_ref_i.lat);
+  int32_t lon_err = abs(lla_result->lon - lla_ref_i.lon);
+  int32_t alt_err = abs(lla_result->alt - lla_ref_i.alt);
+
+  /* max error is 1e-6 deg in lat/lon and 10cm in alt (lla_i is in 1e7deg and mm) */
+  const int32_t max_err_i = 1e-6 * 1e7; // convert to 1e7 deg
+  if (lat_err < max_err_i && lon_err < max_err_i && alt_err < 100) {
+    pass("stateGetPositionLla_i() from ecef_f has max error of 1e-6deg in lat/lon and 10cm in lat");
+  }
+  else {
+    note("lat is %d, should be %d", lla_result->lat, lla_ref_i.lat);
+    note("lon is %d, should be %d", lla_result->lon, lla_ref_i.lon);
+    note("alt is %d, should be %d", lla_result->alt, lla_ref_i.alt);
+    fail("stateGetPositionLla_i() from ecef_f exceeded error of 1e-6deg in lat/lon and 10cm in lat");
+  }
+}
+
+int main()
+{
+  note("\n *** running state interface tests ***");
+  plan(1);
+
+  stateInit();
+
+  test_pos_lla_i();
+
+  done_testing();
+}