diff --git a/Makefile b/Makefile
index a8c47cbf18..6b0df54b92 100644
--- a/Makefile
+++ b/Makefile
@@ -27,9 +27,9 @@ rwildcard=$(strip $(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2)$(filter $
 CC=gcc
 CXX=g++
 CFLAGS=-std=c99
-INCLUDE=-Idescriptor -Icore -Itests -Istream -I.
+INCLUDE=-Idescriptor -Isrc -Itests -I.
 CPPFLAGS=-Wall -Wextra -Wno-missing-field-initializers -g $(INCLUDE) $(strip $(shell test -f perf-cppflags && cat perf-cppflags))
-LDLIBS=-lpthread core/libupb.a
+LDLIBS=-lpthread src/libupb.a
 ifeq ($(shell uname), Darwin)
   CPPFLAGS += -I/usr/include/lua5.1
   LDFLAGS += -L/usr/local/lib -llua
@@ -38,14 +38,14 @@ else
   LDFLAGS += $(strip $(shell pkg-config --silence-errors --libs lua || pkg-config --libs lua5.1))
 endif
 
-LIBUPB=core/libupb.a
-LIBUPB_PIC=core/libupb_pic.a
-LIBUPB_SHARED=core/libupb.so
+LIBUPB=src/libupb.a
+LIBUPB_PIC=src/libupb_pic.a
+LIBUPB_SHARED=src/libupb.so
 ALL=deps $(OBJ) $(LIBUPB) $(LIBUPB_PIC)
 all: $(ALL)
 clean:
 	rm -rf $(LIBUPB) $(LIBUPB_PIC)
-	rm -rf $(call rwildcard,,*.o) $(call rwildcard,,*.lo) $(call rwildcard,,*.gc*)
+	rm -rf $(call rwildcard,,*.o) $(call rwildcard,,*.lo) $(call rwildcard,,*.gcno) $(call rwildcard,,*.dSYM)
 	rm -rf benchmark/google_messages.proto.pb benchmark/google_messages.pb.* benchmarks/b.* benchmarks/*.pb*
 	rm -rf $(TESTS) tests/t.*
 	rm -rf descriptor/descriptor.pb
@@ -59,20 +59,20 @@ deps: gen-deps.sh Makefile $(call rwildcard,,*.c) $(call rwildcard,,*.h)
 # The core library -- the absolute minimum you must compile in to successfully
 # bootstrap.
 CORE= \
-  core/upb.c \
-  core/upb_table.c \
-  core/upb_string.c \
-  core/upb_def.c \
+  src/upb.c \
+  src/upb_table.c \
+  src/upb_string.c \
+  src/upb_def.c \
   descriptor/descriptor.c
 
 # Common encoders/decoders and upb_msg -- you're almost certain to want these.
 STREAM= \
-  stream/upb_decoder.c \
-  stream/upb_stdio.c \
-  stream/upb_textprinter.c \
-  stream/upb_strstream.c \
-  core/upb_msg.c \
-  core/upb_glue.c \
+  src/upb_decoder.c \
+  src/upb_stdio.c \
+  src/upb_textprinter.c \
+  src/upb_strstream.c \
+  src/upb_msg.c \
+  src/upb_glue.c \
 
 SRC=$(CORE) $(STREAM)
 
@@ -81,13 +81,13 @@ $(SRC): perf-cppflags
 OTHERSRC=src/upb_encoder.c src/upb_text.c
 # Override the optimization level for upb_def.o, because it is not in the
 # critical path but gets very large when -O3 is used.
-core/upb_def.o: core/upb_def.c
+src/upb_def.o: src/upb_def.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -Os -c -o $@ $<
-core/upb_def.lo: core/upb_def.c
+src/upb_def.lo: src/upb_def.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -Os -c -o $@ $< -fPIC
 
 lang_ext/lua/upb.so: lang_ext/lua/upb.lo
-	$(CC) $(CFLAGS) $(CPPFLAGS) -shared -o $@ $< core/libupb_pic.a
+	$(CC) $(CFLAGS) $(CPPFLAGS) -shared -o $@ $< src/libupb_pic.a
 
 
 STATICOBJ=$(patsubst %.c,%.o,$(SRC))
@@ -171,10 +171,10 @@ tests/test_table: tests/test_table.cc
 	# Includes <hash_set> which is a deprecated header.
 	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -Wno-deprecated -o $@ $< $(LIBUPB)
 
-tests/tests: core/libupb.a
+tests/tests: src/libupb.a
 
 # Tools
-tools/upbc: core/libupb.a
+tools/upbc: src/libupb.a
 
 # Benchmarks
 #UPB_BENCHMARKS=benchmarks/b.parsetostruct_googlemessage1.upb_table \
diff --git a/core/upb.c b/src/upb.c
similarity index 100%
rename from core/upb.c
rename to src/upb.c
diff --git a/core/upb.h b/src/upb.h
similarity index 100%
rename from core/upb.h
rename to src/upb.h
diff --git a/core/upb_atomic.h b/src/upb_atomic.h
similarity index 100%
rename from core/upb_atomic.h
rename to src/upb_atomic.h
diff --git a/stream/upb_decoder.c b/src/upb_decoder.c
similarity index 100%
rename from stream/upb_decoder.c
rename to src/upb_decoder.c
diff --git a/stream/upb_decoder.h b/src/upb_decoder.h
similarity index 100%
rename from stream/upb_decoder.h
rename to src/upb_decoder.h
diff --git a/core/upb_def.c b/src/upb_def.c
similarity index 100%
rename from core/upb_def.c
rename to src/upb_def.c
diff --git a/core/upb_def.h b/src/upb_def.h
similarity index 100%
rename from core/upb_def.h
rename to src/upb_def.h
diff --git a/stream/upb_encoder.c b/src/upb_encoder.c
similarity index 100%
rename from stream/upb_encoder.c
rename to src/upb_encoder.c
diff --git a/stream/upb_encoder.h b/src/upb_encoder.h
similarity index 100%
rename from stream/upb_encoder.h
rename to src/upb_encoder.h
diff --git a/core/upb_glue.c b/src/upb_glue.c
similarity index 100%
rename from core/upb_glue.c
rename to src/upb_glue.c
diff --git a/core/upb_glue.h b/src/upb_glue.h
similarity index 100%
rename from core/upb_glue.h
rename to src/upb_glue.h
diff --git a/core/upb_msg.c b/src/upb_msg.c
similarity index 100%
rename from core/upb_msg.c
rename to src/upb_msg.c
diff --git a/core/upb_msg.h b/src/upb_msg.h
similarity index 100%
rename from core/upb_msg.h
rename to src/upb_msg.h
diff --git a/stream/upb_stdio.c b/src/upb_stdio.c
similarity index 100%
rename from stream/upb_stdio.c
rename to src/upb_stdio.c
diff --git a/stream/upb_stdio.h b/src/upb_stdio.h
similarity index 100%
rename from stream/upb_stdio.h
rename to src/upb_stdio.h
diff --git a/core/upb_stream.h b/src/upb_stream.h
similarity index 100%
rename from core/upb_stream.h
rename to src/upb_stream.h
diff --git a/core/upb_stream_vtbl.h b/src/upb_stream_vtbl.h
similarity index 100%
rename from core/upb_stream_vtbl.h
rename to src/upb_stream_vtbl.h
diff --git a/core/upb_string.c b/src/upb_string.c
similarity index 100%
rename from core/upb_string.c
rename to src/upb_string.c
diff --git a/core/upb_string.h b/src/upb_string.h
similarity index 100%
rename from core/upb_string.h
rename to src/upb_string.h
diff --git a/stream/upb_strstream.c b/src/upb_strstream.c
similarity index 100%
rename from stream/upb_strstream.c
rename to src/upb_strstream.c
diff --git a/stream/upb_strstream.h b/src/upb_strstream.h
similarity index 100%
rename from stream/upb_strstream.h
rename to src/upb_strstream.h
diff --git a/core/upb_table.c b/src/upb_table.c
similarity index 100%
rename from core/upb_table.c
rename to src/upb_table.c
diff --git a/core/upb_table.h b/src/upb_table.h
similarity index 100%
rename from core/upb_table.h
rename to src/upb_table.h
diff --git a/stream/upb_textprinter.c b/src/upb_textprinter.c
similarity index 100%
rename from stream/upb_textprinter.c
rename to src/upb_textprinter.c
diff --git a/stream/upb_textprinter.h b/src/upb_textprinter.h
similarity index 100%
rename from stream/upb_textprinter.h
rename to src/upb_textprinter.h