diff --git a/ground/openpilotgcs/copydata.pro b/ground/openpilotgcs/copydata.pro
index d7fb31c25..3dd79869e 100644
--- a/ground/openpilotgcs/copydata.pro
+++ b/ground/openpilotgcs/copydata.pro
@@ -233,7 +233,7 @@ GCS_LIBRARY_PATH
             ssleay32.dll \
             libeay32.dll
         for(dll, OPENSSL_DLLS) {
-            data_copy.commands += $(COPY_FILE) $$targetPath(\"$$(OPENSSL_DIR)/$$dll\") $$targetPath(\"$$GCS_APP_PATH/$$dll\") $$addNewline()
+            data_copy.commands += $(COPY_FILE) $$targetPath(\"$${OPENSSL_DIR}/$$dll\") $$targetPath(\"$$GCS_APP_PATH/$$dll\") $$addNewline()
         }
 
         # copy OpenGL DLL
diff --git a/ground/openpilotgcs/openpilotgcs.pri b/ground/openpilotgcs/openpilotgcs.pri
index 8ad271b81..9e2541a84 100644
--- a/ground/openpilotgcs/openpilotgcs.pri
+++ b/ground/openpilotgcs/openpilotgcs.pri
@@ -84,6 +84,7 @@ isEmpty(TOOLS_DIR) {
 }
 
 SDL_DIR = $${TOOLS_DIR}/SDL-1.2.15
+OPENSSL_DIR = $${TOOLS_DIR}/openssl-1.0.1e-win32
 
 GCS_APP_PATH = $$GCS_BUILD_TREE/bin
 macx {
diff --git a/make/tools.mk b/make/tools.mk
index d66dd388d..d990e19a7 100644
--- a/make/tools.mk
+++ b/make/tools.mk
@@ -101,6 +101,7 @@ endif
 GTEST_URL := http://wiki.openpilot.org/download/attachments/18612236/gtest-1.6.0.zip
 
 # Changing PYTHON_DIR, also update it in ground/openpilotgcs/src/python.pri
+# Changing SDL_DIR or OPENSSL_DIR, also update it in ground/openpilotgcs/openpilotgcs.pri
 ARM_SDK_DIR     := $(TOOLS_DIR)/gcc-arm-none-eabi-4_8-2014q1
 QT_SDK_DIR      := $(TOOLS_DIR)/qt-5.3.1
 MINGW_DIR       := $(QT_SDK_DIR)/Tools/mingw48_32