diff --git a/staticlib b/staticlib
index 884b6d5..d2f6eba 100644
--- a/staticlib
+++ b/staticlib
@@ -1,6 +1,7 @@
 CXX:=g++
 INSTALL_PREFIX=/usr/local/
 
+EPI_HEADER_OUT:=build/include/extended-precision-integers/include/epi
 HEADER_OUT:=build/include
 LIB_OUT:=build/lib
 LIB_OUTNAME:=libchacha20.a
@@ -27,7 +28,10 @@ default:
 ifeq ($(OS), Linux)
 	@echo "creating build directory"
 	@mkdir build
-	@mkdir $(HEADER_OUT)
+	@mkdir build/include
+	@mkdir build/include/extended-precision-integers
+	@mkdir build/include/extended-precision-integers/include
+	@mkdir build/include/extended-precision-integers/include/epi
 	@mkdir $(LIB_OUT)
 	@echo "creating static lib"
 	@echo "compiling ChaCha20..."
@@ -38,10 +42,14 @@ ifeq ($(OS), Linux)
 	@echo "moving files to build folder"
 	@mv $(dir $(abspath $(lastword $(MAKEFILE_LIST))))$(LIB_OUTNAME) ./$(LIB_OUT)/
 	@cp $(dir $(abspath $(lastword $(MAKEFILE_LIST))))ChaCha20-Poly1305.hpp ./$(HEADER_OUT)/
+	@cp $(dir $(abspath $(lastword $(MAKEFILE_LIST))))extended-precision-integers/include/epi/epi.hpp ./$(EPI_HEADER_OUT)/
 else
 	@echo "creating build directory"
 	@mkdir build
-	@mkdir "$(HEADER_OUT)"
+	@mkdir build/include
+	@mkdir build/include/extended-precision-integers
+	@mkdir build/include/extended-precision-integers/include
+	@mkdir build/include/extended-precision-integers/include/epi
 	@mkdir "$(LIB_OUT)"
 	@echo "creating static lib"
 	@echo "compiling ChaCha20..."
@@ -52,6 +60,7 @@ else
 	@echo "moving files to build folder"
 	@move "./$(LIB_OUTNAME)" "$(LIB_OUT)"
 	@copy "./ChaCha20-Poly1305.hpp" "$(HEADER_OUT)"
+	@copy "./extended-precision-integers/include/epi/epi.hpp" "$(EPI_HEADER_OUT)"
 endif
 
 cleanup:
@@ -129,8 +138,10 @@ install:
 ifeq ($(OS), Linux)
 	@cp $(dir $(abspath $(lastword $(MAKEFILE_LIST))))$(LIB_OUT)/$(LIB_OUTNAME) $(INSTALL_PREFIX)lib
 	@cp $(dir $(abspath $(lastword $(MAKEFILE_LIST))))$(HEADER_OUT)/ChaCha20-Poly1305.hpp $(INSTALL_PREFIX)include
+	@cp $(dir $(abspath $(lastword $(MAKEFILE_LIST))))$(HEADER_OUT)/extended-precision-integers/include/epi/epi.hpp $(INSTALL_PREFIX)include/extended-precision-integers/include/epi
 	@echo "$(LIB_OUTNAME) now installed to $(INSTALL_PREFIX)lib"
 	@echo "ChaCha20-Poly1305.hpp now installed to $(INSTALL_PREFIX)include"
+	@echo "epi.hpp now installed to $(INSTALL_PREFIX)include/extended-precision-integers/include/epi"
 else
 	@echo .
 	@echo For Mingw64 in windows, please specify your mingw64 folder path with the INSTALL_PREFIX
@@ -139,7 +150,8 @@ else
 	@echo mingw32-make -f staticlib install INSTALL_PREFIX=PATH\mingw64
 	@echo .
 	copy build\lib\$(LIB_OUTNAME) "$(INSTALL_PREFIX)\lib"
-	copy build\include\ChaCha20-Poly1305.hpp "$(INSTALL_PREFIX)\include
+	copy build\include\ChaCha20-Poly1305.hpp "$(INSTALL_PREFIX)\include"
+	copy build\include\extended-precision-integers\include\epi\epi.hpp "$(INSTALL_PREFIX)\include\extended-precision-integers\include\epi"
 	@echo install success
 endif
 
@@ -147,8 +159,10 @@ uninstall:
 ifeq ($(OS), Linux)
 	@rm $(INSTALL_PREFIX)lib/$(LIB_OUTNAME)
 	@rm $(INSTALL_PREFIX)include/ChaCha20-Poly1305.hpp
+	@rm $(INSTALL_PREFIX)include/extended-precision-integers/include/epi/epi.hpp
 else
 	del "$(INSTALL_PREFIX)\lib\$(LIB_OUTNAME)"
 	del "$(INSTALL_PREFIX)\include\ChaCha20-Poly1305.hpp"
+	del "$(INSTALL_PREFIX)\include\extended-precision-integers\include\epi\epi.hpp"
 	echo uninstall success
 endif
\ No newline at end of file