diff --git a/Makefile b/Makefile
index 669ac9f6d..59d089866 100644
--- a/Makefile
+++ b/Makefile
@@ -19,14 +19,14 @@ LINK_LOCAL_DIR=-L.
 LINK_LIB=-l$(1)
 CFLAGS_OPT=-O3
 CFLAGS_DEBUG=-g
-BUILDTYPE=Release
+BUILDTYPE?=Release
 V=Yes
-PREFIX=/usr/local
+PREFIX?=/usr/local
 SHARED=-shared
 OBJ=o
 DESTDIR=
-LIBDIR_NAME=lib
-SHAREDLIB_DIR=$(PREFIX)/lib
+LIBDIR_NAME?=lib
+SHAREDLIB_DIR?=$(PREFIX)/lib
 PROJECT_NAME=openh264
 MODULE_NAME=gmpopenh264
 GMP_API_BRANCH=Firefox114_2
@@ -298,10 +298,10 @@ endif
 endif
 
 $(PROJECT_NAME).pc: $(PROJECT_NAME).pc.in
-	@sed -e 's;@prefix@;$(PREFIX);' -e 's;@libdir@;$(PREFIX)/lib;' -e 's;@VERSION@;$(FULL_VERSION);' -e 's;@LIBS@;;' -e 's;@LIBS_PRIVATE@;$(STATIC_LDFLAGS);' < $< > $@
+	@sed -e 's;@prefix@;$(PREFIX);' -e 's;@libdir@;$(PREFIX)/$(LIBDIR_NAME);' -e 's;@VERSION@;$(FULL_VERSION);' -e 's;@LIBS@;;' -e 's;@LIBS_PRIVATE@;$(STATIC_LDFLAGS);' < $< > $@
 
 $(PROJECT_NAME)-static.pc: $(PROJECT_NAME).pc.in
-	@sed -e 's;@prefix@;$(PREFIX);' -e 's;@libdir@;$(PREFIX)/lib;' -e 's;@VERSION@;$(FULL_VERSION);' -e 's;@LIBS@;$(STATIC_LDFLAGS);' -e 's;@LIBS_PRIVATE@;;' < $< > $@
+	@sed -e 's;@prefix@;$(PREFIX);' -e 's;@libdir@;$(PREFIX)/$(LIBDIR_NAME);' -e 's;@VERSION@;$(FULL_VERSION);' -e 's;@LIBS@;$(STATIC_LDFLAGS);' -e 's;@LIBS_PRIVATE@;;' < $< > $@
 
 install-headers:
 	mkdir -p $(DESTDIR)$(PREFIX)/include/wels