diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 0000000..c0e1ae0
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,40 @@
+skip_branch_with_pr: true
+os: 'Visual Studio 2015'
+
+build: off
+
+environment:
+  matrix:
+    - ARCH: x64
+      MSYS2_ARCH: x86_64
+      MSYS2_DIR: msys64
+      MSYSTEM: MINGW64
+      GOPATH: c:\gopath
+      GOROOT: c:\go
+      GOARCH: amd64
+      EXTLD: x86_64-w64-mingw32-gcc
+    - ARCH: x86
+      MSYS2_ARCH: i686
+      MSYS2_DIR: msys64
+      MSYSTEM: MINGW32
+      GOPATH: c:\gopath
+      GOROOT: c:\go
+      GOARCH: 386
+      EXTLD: i686-w64-mingw32-gcc
+
+clone_folder: C:\gopath\src\github.com\mastahyeti\certstore
+
+before_test:
+  # Ensure CGO is enabled
+  - set CGO_ENABLED=1
+  # Go paths
+  - set PATH=%GOROOT%\bin;C:\%GOPATH%\bin;%PATH%
+  # MSYS paths
+  - set PATH=C:\%MSYS2_DIR%\%MSYSTEM%\bin;C:\%MSYS2_DIR%\usr\bin;%PATH%
+  # Install build deps
+  - bash -lc "for n in `seq 1 3`; do pacman --noconfirm -S mingw-w64-%MSYS2_ARCH%-libtool && break || sleep 15; done"
+  # Install Go deps
+  - go get -t -v ./...
+
+test_script:
+  - go test -v ./...
diff --git a/appveyor.yml b/appveyor.yml
deleted file mode 100644
index 11b0ef8..0000000
--- a/appveyor.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-version: "{build}"
-clone_folder: c:\gopath\src\github.com\mastahyeti\certstore
-environment:
-  GOPATH: c:\gopath
-
-install:
-  - set PATH=%PATH%;C:\msys64\mingw64\bin
-  - go version
-  - go get -t -v ./...
-build_script:
-  - go build
-test_script:
-  - go test -v
diff --git a/certstore_windows.go b/certstore_windows.go
index aa8a628..8c09e97 100644
--- a/certstore_windows.go
+++ b/certstore_windows.go
@@ -112,18 +112,18 @@ func (s *winStore) Identities() ([]Identity, error) {
 			goto fail
 		}
 
-		// maximum chain length. this is arbitrary
-		const maxChain = 1 << 30
+		// not sure why this isn't 1 << 29
+		const maxPointerArray = 1 << 28
 
 		// rgpChain is actually an array, but we only care about the first one.
 		simpleChain := *chainCtx.rgpChain
-		if simpleChain.cElement < 1 || simpleChain.cElement > maxChain {
+		if simpleChain.cElement < 1 || simpleChain.cElement > maxPointerArray {
 			err = errors.New("bad chain")
 			goto fail
 		}
 
 		// Hacky way to get chain elements (c array) as a slice.
-		chainElts := (*[maxChain]C.PCERT_CHAIN_ELEMENT)(unsafe.Pointer(simpleChain.rgpElement))[:simpleChain.cElement:simpleChain.cElement]
+		chainElts := (*[maxPointerArray]C.PCERT_CHAIN_ELEMENT)(unsafe.Pointer(simpleChain.rgpElement))[:simpleChain.cElement:simpleChain.cElement]
 
 		// Build chain of certificates from each elt's certificate context.
 		chain := make([]C.PCCERT_CONTEXT, len(chainElts))
@@ -654,10 +654,17 @@ func (ss securityStatus) Error() string {
 }
 
 func stringToUTF16(s string) C.LPCWSTR {
+	// Not sure why this isn't 1 << 30...
+	const maxUint16Array = 1 << 29
+
+	if len(s) > maxUint16Array {
+		panic("string too long")
+	}
+
 	wstr := utf16.Encode([]rune(s))
 
 	p := C.calloc(C.size_t(len(wstr)+1), C.size_t(unsafe.Sizeof(uint16(0))))
-	pp := (*[1 << 30]uint16)(p)
+	pp := (*[maxUint16Array]uint16)(p)
 	copy(pp[:], wstr)
 
 	return (C.LPCWSTR)(p)