diff --git a/build/rules.mk b/build/rules.mk
index 0dd60984d..6d11c6da3 100644
--- a/build/rules.mk
+++ b/build/rules.mk
@@ -116,10 +116,6 @@ o/$(MODE)/%.lua: %.lua o/$(MODE)/third_party/lua/luac.com $(VM)
 o/$(MODE)/%.lua.runs: %.lua o/$(MODE)/tool/net/redbean.com $(VM)
 	@$(COMPILE) -wALUA -tT$@ $(VM) o/$(MODE)/tool/net/redbean.com $(LUAFLAGS) -i $<
 
-o/$(MODE)/%: o/$(MODE)/%.com o/$(MODE)/tool/build/cp.com o/$(MODE)/tool/build/assimilate.com $(VM)
-	@$(COMPILE) -wACP -T$@ $(VM) o/$(MODE)/tool/build/cp.com $< $@
-	@$(COMPILE) -wAASSIMILATE -T$@ $(VM) o/$(MODE)/tool/build/assimilate.com $@
-
 ################################################################################
 # LOCAL UNIT TESTS
 #
diff --git a/test/libc/stdio/dirstream_test.c b/test/libc/stdio/dirstream_test.c
index 8d7d672d2..cf4909779 100644
--- a/test/libc/stdio/dirstream_test.c
+++ b/test/libc/stdio/dirstream_test.c
@@ -61,7 +61,7 @@ TEST(opendir, enotdir) {
 TEST(opendir, zipTest_fake) {
   ASSERT_NE(NULL, (dir = opendir("/zip")));
   EXPECT_NE(NULL, (ent = readdir(dir)));
-  EXPECT_STREQ("echo", ent->d_name);
+  EXPECT_STREQ("echo.com", ent->d_name);
   EXPECT_NE(NULL, (ent = readdir(dir)));
   EXPECT_STREQ("usr", ent->d_name);
   EXPECT_NE(NULL, (ent = readdir(dir)));
@@ -70,7 +70,7 @@ TEST(opendir, zipTest_fake) {
   EXPECT_EQ(0, closedir(dir));
   ASSERT_NE(NULL, (dir = opendir("/zip/")));
   EXPECT_NE(NULL, (ent = readdir(dir)));
-  EXPECT_STREQ("echo", ent->d_name);
+  EXPECT_STREQ("echo.com", ent->d_name);
   EXPECT_NE(NULL, (ent = readdir(dir)));
   EXPECT_STREQ("usr", ent->d_name);
   EXPECT_NE(NULL, (ent = readdir(dir)));
diff --git a/test/libc/stdio/test.mk b/test/libc/stdio/test.mk
index 1d9b8c389..b2ad38268 100644
--- a/test/libc/stdio/test.mk
+++ b/test/libc/stdio/test.mk
@@ -57,7 +57,7 @@ o/$(MODE)/test/libc/stdio/%.com.dbg:				\
 		$(TEST_LIBC_STDIO_DEPS)				\
 		o/$(MODE)/test/libc/stdio/%.o			\
 		o/$(MODE)/test/libc/stdio/stdio.pkg		\
-		o/$(MODE)/tool/build/echo.zip.o			\
+		o/$(MODE)/tool/build/echo.com.zip.o		\
 		$(LIBC_TESTMAIN)				\
 		$(CRT)						\
 		$(APE_NO_MODIFY_SELF)
diff --git a/tool/build/build.mk b/tool/build/build.mk
index dc7c404b5..d193d97d0 100644
--- a/tool/build/build.mk
+++ b/tool/build/build.mk
@@ -9,16 +9,7 @@ TOOL_BUILD_HDRS = $(filter %.h,$(TOOL_BUILD_FILES))
 
 TOOL_BUILD_BINS =					\
 	$(TOOL_BUILD_COMS)				\
-	$(TOOL_BUILD_COMS:%=%.dbg)			\
-	o/$(MODE)/tool/build/mkdir			\
-	o/$(MODE)/tool/build/chmod			\
-	o/$(MODE)/tool/build/cp				\
-	o/$(MODE)/tool/build/mv				\
-	o/$(MODE)/tool/build/echo			\
-	o/$(MODE)/tool/build/false			\
-	o/$(MODE)/tool/build/gzip			\
-	o/$(MODE)/tool/build/printf			\
-	o/$(MODE)/tool/build/dd
+	$(TOOL_BUILD_COMS:%=%.dbg)
 
 TOOL_BUILD_OBJS =					\
 	$(TOOL_BUILD_SRCS:%.c=o/$(MODE)/%.o)
@@ -85,18 +76,9 @@ o/$(MODE)/tool/build/%.com.dbg:				\
 	@$(APELINK)
 
 o/$(MODE)/tool/build/dso/sandbox.so.zip.o		\
-o/$(MODE)/tool/build/mkdir.zip.o			\
-o/$(MODE)/tool/build/chmod.zip.o			\
-o/$(MODE)/tool/build/cp.zip.o				\
-o/$(MODE)/tool/build/mv.zip.o				\
-o/$(MODE)/tool/build/false.zip.o			\
 o/$(MODE)/tool/build/false.com.zip.o			\
-o/$(MODE)/tool/build/echo.zip.o				\
 o/$(MODE)/tool/build/echo.com.zip.o			\
-o/$(MODE)/tool/build/cocmd.com.zip.o			\
-o/$(MODE)/tool/build/gzip.zip.o				\
-o/$(MODE)/tool/build/printf.zip.o			\
-o/$(MODE)/tool/build/dd.zip.o: private			\
+o/$(MODE)/tool/build/cocmd.com.zip.o: private		\
 		ZIPOBJ_FLAGS +=				\
 			-B