diff --git a/Makefile b/Makefile
index f18ca43..14cba8a 100644
--- a/Makefile
+++ b/Makefile
@@ -3,39 +3,44 @@ FLAGS_PROD:=-DNDEBUG -O2 -march=native
 FLAGS_DEBUG:=-DVERIFY -ggdb3 -O1
 FLAGS_TEST:=-DVERIFY -ggdb3 -O2 -march=native
 
-SECP256K1_FILES := num.h   field.h   field_5x52.h   group.h   ecmult.h   ecdsa.h   \
-                   num.cpp field.cpp field_5x52.cpp group.cpp ecmult.cpp ecdsa.cpp
+SECP256K1_FILES := src/num.h   src/field.h   src/field_5x52.h   src/group.h   src/ecmult.h   src/ecdsa.h   \
+                   src/num.cpp src/field.cpp src/field_5x52.cpp src/group.cpp src/ecmult.cpp src/ecdsa.cpp
+
 
 ifndef CONF
 CONF := gmp
 endif
 
+OBJS := obj/secp256k1-$(CONF).o
+
 default: all
 
 ifeq ($(CONF), openssl)
-FLAGS_CONF:=-DUSE_NUM_OPENSSL -DUSE_FIELDINVERSE_BUILTIN
+FLAGS_CONF:=-DUSE_NUM_OPENSSL -DUSE_FIELD_INV_BUILTIN
 LIBS:=-lcrypto
-SECP256K1_FILES := $(SECP256K1_FILES) num_openssl.h num_openssl.cpp field_5x52_int128.cpp
+SECP256K1_FILES := $(SECP256K1_FILES) src/num_openssl.h src/num_openssl.cpp src/field_5x52_int128.cpp
 else
 ifeq ($(CONF), gmp)
 FLAGS_CONF:=-DUSE_NUM_GMP
 LIBS:=-lgmp
-SECP256K1_FILES := $(SECP256K1_FILES) num_gmp.h num_gmp.cpp field_5x52_int128.cpp
+SECP256K1_FILES := $(SECP256K1_FILES) src/num_gmp.h src/num_gmp.cpp src/field_5x52_int128.cpp
 else
 ifeq ($(CONF), gmpasm)
-FLAGS_CONF:=-DUSE_NUM_GMP -DINLINE_ASM
+FLAGS_CONF:=-DUSE_NUM_GMP -DUSE_FIELD_5X52_ASM
 LIBS:=-lgmp obj/field_5x52_asm.o
-SECP256K1_FILES := $(SECP256K1_FILES) num_gmp.h num_gmp.cpp field_5x52_asm.cpp obj/field_5x52_asm.o
+OBJS:=$(OBJS) obj/field_5x52_asm.o
+SECP256K1_FILES := $(SECP256K1_FILES) src/num_gmp.h src/num_gmp.cpp src/field_5x52_asm.cpp
 
-obj/field_5x52_asm.o: field_5x52_asm.asm
-	yasm -f elf64 -o obj/field_5x52_asm.o field_5x52_asm.asm
+obj/field_5x52_asm.o: src/field_5x52_asm.asm
+	yasm -f elf64 -o obj/field_5x52_asm.o src/field_5x52_asm.asm
 else
-SECP256K1_FILES := $(SECP256K1_FILES) field_5x52_int128.cpp
+SECP256K1_FILES := $(SECP256K1_FILES) src/field_5x52_int128.cpp
 endif
 endif
 endif
 
-all: *.cpp *.asm *.h
+
+all: src/*.cpp src/*.asm src/*.h include/*.h
 	+make CONF=openssl all-openssl
 	+make CONF=gmp     all-gmp
 	+make CONF=gmpasm  all-gmpasm
@@ -48,16 +53,19 @@ clean:
 bench-any: bench-$(CONF)
 tests-any: tests-$(CONF)
 
-all-$(CONF): bench-$(CONF) tests-$(CONF) obj/secp256k1-$(CONF).o
+all-$(CONF): bench-$(CONF) tests-$(CONF) libsecp256k1-$(CONF).a
 
 clean-$(CONF):
-	rm -f bench-$(CONF) tests-$(CONF) obj/secp256k1-$(CONF).o
+	rm -f bench-$(CONF) tests-$(CONF) libsecp256k1-$(CONF).a obj/*
 
-obj/secp256k1-$(CONF).o: $(SECP256K1_FILES)
-	$(CXX) $(FLAGS_COMMON) $(FLAGS_PROD) $(FLAGS_CONF) secp256k1.cpp -c -o obj/secp256k1-$(CONF).o
+obj/secp256k1-$(CONF).o: $(SECP256K1_FILES) src/secp256k1.cpp include/secp256k1.h
+	$(CXX) $(FLAGS_COMMON) $(FLAGS_PROD) $(FLAGS_CONF) src/secp256k1.cpp -c -o obj/secp256k1-$(CONF).o
 
-bench-$(CONF): $(SECP256K1_FILES) bench.cpp
-	$(CXX) $(FLAGS_COMMON) $(FLAGS_PROD) $(FLAGS_CONF) bench.cpp $(LIBS) -o bench-$(CONF)
+bench-$(CONF): $(OBJS) src/bench.cpp
+	$(CXX) $(FLAGS_COMMON) $(FLAGS_PROD) $(FLAGS_CONF) src/bench.cpp $(LIBS) -o bench-$(CONF)
 
-tests-$(CONF): $(SECP256K1_FILES) tests.cpp
-	$(CXX) $(FLAGS_COMMON) $(FLAGS_TEST) $(FLAGS_CONF) tests.cpp $(LIBS) -o tests-$(CONF)
+tests-$(CONF): $(OBJS) src/tests.cpp
+	$(CXX) $(FLAGS_COMMON) $(FLAGS_TEST) $(FLAGS_CONF) src/tests.cpp $(LIBS) -o tests-$(CONF)
+
+libsecp256k1-$(CONF).a: $(OBJS)
+	$(AR) -rs $@ $(OBJS)
diff --git a/secp256k1.h b/include/secp256k1.h
similarity index 100%
rename from secp256k1.h
rename to include/secp256k1.h
diff --git a/bench.cpp b/src/bench.cpp
similarity index 100%
rename from bench.cpp
rename to src/bench.cpp
diff --git a/ecdsa.cpp b/src/ecdsa.cpp
similarity index 100%
rename from ecdsa.cpp
rename to src/ecdsa.cpp
diff --git a/ecdsa.h b/src/ecdsa.h
similarity index 100%
rename from ecdsa.h
rename to src/ecdsa.h
diff --git a/ecmult.cpp b/src/ecmult.cpp
similarity index 100%
rename from ecmult.cpp
rename to src/ecmult.cpp
diff --git a/ecmult.h b/src/ecmult.h
similarity index 100%
rename from ecmult.h
rename to src/ecmult.h
diff --git a/field.cpp b/src/field.cpp
similarity index 99%
rename from field.cpp
rename to src/field.cpp
index 9c214e6..94d19d6 100644
--- a/field.cpp
+++ b/src/field.cpp
@@ -135,7 +135,7 @@ void static secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
 }
 
 void static secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
-#if defined(USE_FIELDINVERSE_BUILTIN)
+#if defined(USE_FIELD_INV_BUILTIN)
     secp256k1_fe_inv(r, a);
 #else
     unsigned char b[32];
diff --git a/field.h b/src/field.h
similarity index 100%
rename from field.h
rename to src/field.h
diff --git a/field_5x52.cpp b/src/field_5x52.cpp
similarity index 99%
rename from field_5x52.cpp
rename to src/field_5x52.cpp
index acc4444..3f063b3 100644
--- a/field_5x52.cpp
+++ b/src/field_5x52.cpp
@@ -3,7 +3,7 @@
 #include "num.h"
 #include "field.h"
 
-#ifdef INLINE_ASM
+#ifdef USE_FIELD_5X52_ASM
 #include "field_5x52_asm.cpp"
 #else
 #include "field_5x52_int128.cpp"
diff --git a/field_5x52.h b/src/field_5x52.h
similarity index 100%
rename from field_5x52.h
rename to src/field_5x52.h
diff --git a/field_5x52_asm.asm b/src/field_5x52_asm.asm
similarity index 100%
rename from field_5x52_asm.asm
rename to src/field_5x52_asm.asm
diff --git a/field_5x52_asm.cpp b/src/field_5x52_asm.cpp
similarity index 100%
rename from field_5x52_asm.cpp
rename to src/field_5x52_asm.cpp
diff --git a/field_5x52_int128.cpp b/src/field_5x52_int128.cpp
similarity index 100%
rename from field_5x52_int128.cpp
rename to src/field_5x52_int128.cpp
diff --git a/group.cpp b/src/group.cpp
similarity index 100%
rename from group.cpp
rename to src/group.cpp
diff --git a/group.h b/src/group.h
similarity index 100%
rename from group.h
rename to src/group.h
diff --git a/num.cpp b/src/num.cpp
similarity index 100%
rename from num.cpp
rename to src/num.cpp
diff --git a/num.h b/src/num.h
similarity index 100%
rename from num.h
rename to src/num.h
diff --git a/num_builtin.h b/src/num_builtin.h
similarity index 100%
rename from num_builtin.h
rename to src/num_builtin.h
diff --git a/num_gmp.cpp b/src/num_gmp.cpp
similarity index 100%
rename from num_gmp.cpp
rename to src/num_gmp.cpp
diff --git a/num_gmp.h b/src/num_gmp.h
similarity index 100%
rename from num_gmp.h
rename to src/num_gmp.h
diff --git a/num_openssl.cpp b/src/num_openssl.cpp
similarity index 100%
rename from num_openssl.cpp
rename to src/num_openssl.cpp
diff --git a/num_openssl.h b/src/num_openssl.h
similarity index 100%
rename from num_openssl.h
rename to src/num_openssl.h
diff --git a/num_openssl_.cpp b/src/num_openssl_.cpp
similarity index 100%
rename from num_openssl_.cpp
rename to src/num_openssl_.cpp
diff --git a/secp256k1.cpp b/src/secp256k1.cpp
similarity index 100%
rename from secp256k1.cpp
rename to src/secp256k1.cpp
diff --git a/tests.cpp b/src/tests.cpp
similarity index 100%
rename from tests.cpp
rename to src/tests.cpp