diff --git a/CronosAgent.c b/CronosAgent.c
index 67ff0df..c8adb24 100644
--- a/CronosAgent.c
+++ b/CronosAgent.c
@@ -17,7 +17,10 @@
 #include <sys/time.h>
 #include <sys/socket.h>
 
-// #include <openssl/sha.h>
+#ifdef USE_OPENSSL
+#include <openssl/sha.h>
+#endif
+
 #ifndef HEADER_SHA_H
 #include "sha256.h"
 #define SHA256_DIGEST_LENGTH  SHA256_BLOCK_SIZE
diff --git a/Makefile b/Makefile
index ba15702..4bdb57f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,37 +1,41 @@
+USE_OPENSSL := no
+
 BUILD := $(shell date -u +%Y%m%d-%H%M%S)
 OS := $(shell uname -s)
 
 PREFIX = $(DESTDIR)/opt/CronosAgent
 
-DIRECTORIES = 
-
 ifeq ($(OS), Linux)
-  LIBRARIES += \
-    rt
-#  DEPENDENCIES = \
-#    openssl
+  FLAGS += -rdynamic
+  LIBRARIES += rt
+ifeq ($(USE_OPENSSL), yes)
+  FLAGS += -DUSE_OPENSSL
+  DEPENDENCIES += openssl
+endif
 endif
 
 ifeq ($(OS), Darwin)
-  CFLAGS += \
-    -Wno-deprecated-declarations
-#   -I/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift-migrator/sdk/MacOSX.sdk/usr/include/
-#  LIBRARIES += \
-#    crypto
+  FLAGS += -Wno-deprecated-declarations
+ifeq ($(USE_OPENSSL), yes)
+  FLAGS += -DUSE_OPENSSL -I/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift-migrator/sdk/MacOSX.sdk/usr/include/
+  LIBRARIES += crypto
+endif
 endif
 
-OBJECTS = \
-  sha256.o \
-  CronosAgent.o
+OBJECTS = CronosAgent.o
 
-FLAGS := -g -fno-omit-frame-pointer -O3 -MMD $(foreach directory, $(DIRECTORIES), -I$(directory)) -DBUILD=\"$(BUILD)\"
-LIBS := $(foreach library, $(LIBRARIES), -l$(library))
+ifneq ($(USE_OPENSSL), yes)
+  OBJECTS += sha256.o
+endif
+
+FLAGS += -g -fno-omit-frame-pointer -O3 -MMD $(foreach directory, $(DIRECTORIES), -I$(directory)) -DBUILD=\"$(BUILD)\"
+LIBS += $(foreach library, $(LIBRARIES), -l$(library))
 
 CC = gcc
 CFLAGS += $(FLAGS) -std=gnu99
 
-ifeq ($(OS), Linux)
-  FLAGS += $(shell pkg-config --cflags $(DEPENDENCIES)) -rdynamic
+ifneq ($(strip $(DEPENDENCIES)),)
+  FLAGS += $(shell pkg-config --cflags $(DEPENDENCIES))
   LIBS += $(shell pkg-config --libs $(DEPENDENCIES))
 endif
 
diff --git a/cronosagent.sh b/cronosagent.sh
index b5de2e5..37bb4d5 100755
--- a/cronosagent.sh
+++ b/cronosagent.sh
@@ -5,7 +5,8 @@ DIRECTORY=$(dirname $0)
 if [ -f $DIRECTORY/cronosagent.conf ]
 then
   # Read configuration from text file
-  source $DIRECTORY/cronosagent.conf
+  # Dot is equivalent of bash's source
+  . $DIRECTORY/cronosagent.conf
 fi
 
 if [ -f /etc/config/cronosagent ]