diff --git a/Cryptlib/Makefile b/Cryptlib/Makefile
index 5c098f3..18a33b1 100644
--- a/Cryptlib/Makefile
+++ b/Cryptlib/Makefile
@@ -1,7 +1,7 @@
 
 EFI_INCLUDES	= -I$(TOPDIR)/Include -I$(EFI_INCLUDE) -I$(EFI_INCLUDE)/$(ARCH) -I$(EFI_INCLUDE)/protocol
 
-CFLAGS		= -ggdb -O0 -I$(TOPDIR) -iquote $(TOPDIR) -fno-stack-protector -fno-strict-aliasing -fpic -fshort-wchar \
+CFLAGS		= -ggdb $(OPTIMIZATIONS) -I$(TOPDIR) -iquote $(TOPDIR) -fno-stack-protector -fno-strict-aliasing -fpic -fshort-wchar \
 		  -Wall $(EFI_INCLUDES) -std=gnu89 \
 		  -ffreestanding -I$(shell $(CC) -print-file-name=include)
 
diff --git a/Cryptlib/OpenSSL/Makefile b/Cryptlib/OpenSSL/Makefile
index 916feac..9a7697c 100644
--- a/Cryptlib/OpenSSL/Makefile
+++ b/Cryptlib/OpenSSL/Makefile
@@ -3,7 +3,7 @@ EFI_INCLUDES	= -I$(TOPDIR)/../Include \
 		  -I$(EFI_INCLUDE) -I$(EFI_INCLUDE)/$(ARCH) -I$(EFI_INCLUDE)/protocol \
 		  -I$(TOPDIR)/crypto/asn1 -I$(TOPDIR)/crypto/evp -I$(TOPDIR)/crypto/modes -I$(TOPDIR)/crypto/include
 
-CFLAGS		= -ggdb -O0 -I$(TOPDIR) -I$(TOPDIR)/.. -I$(TOPDIR)/../Include/ -I$(TOPDIR)/crypto \
+CFLAGS		= -ggdb $(OPTIMIZATIONS) -I$(TOPDIR) -I$(TOPDIR)/.. -I$(TOPDIR)/../Include/ -I$(TOPDIR)/crypto \
 		  -fno-stack-protector -fno-strict-aliasing -fpic -fshort-wchar -nostdinc \
 		  -ffreestanding -std=gnu89 -I$(shell $(CC) -print-file-name=include) \
 		  -Wall $(EFI_INCLUDES) -DL_ENDIAN -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE -DOPENSSL_SMALL_FOOTPRINT -DPEDANTIC
diff --git a/Make.defaults b/Make.defaults
index e58a281..e85e957 100644
--- a/Make.defaults
+++ b/Make.defaults
@@ -27,6 +27,7 @@ DASHJ		?= -j$(shell echo $$(($$(grep -c "^model name" /proc/cpuinfo) + 1)))
 
 ARCH		?= $(shell $(CC) -dumpmachine | cut -f1 -d- | sed s,i[3456789]86,ia32,)
 OBJCOPY_GTE224	= $(shell expr `$(OBJCOPY) --version |grep ^"GNU objcopy" | sed 's/^.*\((.*)\|version\) //g' | cut -f1-2 -d.` \>= 2.24)
+OPTIMIZATIONS	?= -Os
 
 SUBDIRS		= $(TOPDIR)/Cryptlib $(TOPDIR)/lib
 
@@ -87,7 +88,7 @@ ifeq ($(ARCH),arm)
 	TIMESTAMP_LOCATION	:= 72
 endif
 
-CFLAGS		= -ggdb -O0 -fno-stack-protector -fno-strict-aliasing -fpic \
+CFLAGS		= -ggdb $(OPTIMIZATIONS) -fno-stack-protector -fno-strict-aliasing -fpic \
 		  -fshort-wchar -Wall -Wsign-compare -Werror -fno-builtin \
 		  -Werror=sign-compare -ffreestanding -std=gnu89 \
 		  -I$(shell $(CC) $(ARCH_CFLAGS) -print-file-name=include) \
diff --git a/Makefile b/Makefile
index 226f08d..eaed19a 100644
--- a/Makefile
+++ b/Makefile
@@ -279,4 +279,4 @@ archive: tag
 
 .PHONY : install-deps shim.key
 
-export ARCH CC LD OBJCOPY EFI_INCLUDE
+export ARCH CC LD OBJCOPY EFI_INCLUDE OPTIMIZATIONS