diff --git a/binding.gyp b/binding.gyp
index d78f6eb..54f2568 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -4,7 +4,58 @@
       "target_name": "worker",
       "include_dirs": ["<!(node -e \"require('nan')\")"],
       "cflags": ["-Wall", "-O2"],
-      "sources": ["src/worker.cc", "src/pow.cc"]
+      "sources": ["src/worker.cc", "src/pow.cc"],
+      "conditions": [
+        ["OS=='win'", {
+          "conditions": [
+            [
+              "target_arch=='x64'", {
+                "variables": {
+                  "openssl_root%": "C:/OpenSSL-Win64"
+                },
+              }, {
+                "variables": {
+                  "openssl_root%": "C:/OpenSSL-Win32"
+                }
+              }
+            ]
+          ],
+          "libraries": [
+            "-l<(openssl_root)/lib/libeay32.lib",
+          ],
+          "include_dirs": [
+            "<(openssl_root)/include",
+          ],
+        }, {
+          "conditions": [
+            [
+              "target_arch=='ia32'", {
+                "variables": {
+                  "openssl_config_path": "<(nodedir)/deps/openssl/config/piii"
+                }
+              }
+            ],
+            [
+              "target_arch=='x64'", {
+                "variables": {
+                  "openssl_config_path": "<(nodedir)/deps/openssl/config/k8"
+                },
+              }
+            ],
+            [
+              "target_arch=='arm'", {
+                "variables": {
+                  "openssl_config_path": "<(nodedir)/deps/openssl/config/arm"
+                }
+              }
+            ],
+          ],
+          "include_dirs": [
+            "<(nodedir)/deps/openssl/openssl/include",
+            "<(openssl_config_path)"
+          ]
+        }
+      ]]
     }
   ]
 }
diff --git a/package.json b/package.json
index bdceed5..25b95cb 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,6 @@
     "mocha": "*"
   },
   "dependencies": {
-    "bignum": "^0.9.0",
     "bn.js": "^1.0.0",
     "bs58": "^2.0.0",
     "buffer-equal": "~0.0.1",
@@ -58,5 +57,8 @@
     "object-assign": "^2.0.0",
     "sha.js": "^2.3.1",
     "webworkify": "^1.0.1"
+  },
+  "optionalDependencies": {
+    "bignum": "^0.9.0"
   }
 }