diff --git a/sycl/source/detail/force_device.cpp b/sycl/source/detail/force_device.cpp
index e23c53704405d..f261f24480052 100644
--- a/sycl/source/detail/force_device.cpp
+++ b/sycl/source/detail/force_device.cpp
@@ -9,6 +9,8 @@
 #include <CL/sycl/detail/force_device.hpp>
 #include <CL/sycl/info/info_desc.hpp>
 #include <CL/sycl/stl.hpp>
+
+#include <algorithm>
 #include <cstdlib>
 
 __SYCL_INLINE_NAMESPACE(cl) {
@@ -21,18 +23,23 @@ bool match_types(const info::device_type &l, const info::device_type &r) {
 
 info::device_type get_forced_type() {
   if (const char *val = std::getenv("SYCL_DEVICE_TYPE")) {
-    if (string_class(val) == "CPU") {
+    std::string type(val);
+    std::transform(type.begin(), type.end(), type.begin(), ::tolower);
+
+    if (type == "cpu") {
       return info::device_type::cpu;
     }
-    if (string_class(val) == "GPU") {
+    if (type == "gpu") {
       return info::device_type::gpu;
     }
-    if (string_class(val) == "ACC") {
+    if (type == "acc") {
       return info::device_type::accelerator;
     }
-    if (string_class(val) == "HOST") {
+    if (type == "host") {
       return info::device_type::host;
     }
+    throw cl::sycl::runtime_error("SYCL_DEVICE_TYPE is not recognized.  Must "
+                                  "be GPU, CPU, ACC or HOST.");
   }
   return info::device_type::all;
 }
diff --git a/sycl/test/basic_tests/diagnostics/device-check.cpp b/sycl/test/basic_tests/diagnostics/device-check.cpp
new file mode 100644
index 0000000000000..1eee76668a5cb
--- /dev/null
+++ b/sycl/test/basic_tests/diagnostics/device-check.cpp
@@ -0,0 +1,50 @@
+// RUN: %clangxx -fsycl %s -o %t.out
+// RUN: env SYCL_DEVICE_TYPE=cpu %t.out
+// RUN: env SYCL_DEVICE_TYPE=gpu %t.out
+// RUN: env SYCL_DEVICE_TYPE=acc %t.out
+// RUN: env SYCL_DEVICE_TYPE=host %t.out
+// RUN: env SYCL_DEVICE_TYPE=CPU %t.out
+// RUN: env SYCL_DEVICE_TYPE=GPU %t.out
+// RUN: env SYCL_DEVICE_TYPE=ACC %t.out
+// RUN: env SYCL_DEVICE_TYPE=HOST %t.out
+// RUN: env SYCL_DEVICE_TYPE=Cpu %t.out
+// RUN: env SYCL_DEVICE_TYPE=Gpu %t.out
+// RUN: env SYCL_DEVICE_TYPE=Acc %t.out
+// RUN: env SYCL_DEVICE_TYPE=Host %t.out
+// RUN: env SYCL_DEVICE_TYPE=XPU %t.out
+
+//==------------------- device-check.cpp --------------------------==//
+// This is a diagnostic test which ensures that
+// device types are case-insensitive.
+// It also checks for SYCL_DEVICE being set incorrectly.
+//==---------------------------------------------------------------==//
+
+#include <CL/sycl.hpp>
+#include <iostream>
+
+using namespace cl::sycl;
+
+
+int main() {
+  try {
+    queue q = queue();
+    auto device = q.get_device();
+    auto deviceName = device.get_info<cl::sycl::info::device::name>();
+    std::cout << " Device Name: " << deviceName << std::endl;
+  }
+
+  catch (runtime_error &E) {
+    if (std::string(E.what()).find(
+        "SYCL_DEVICE_TYPE is not recognized.  Must be GPU, CPU, ACC or HOST.") ==
+        std::string::npos) {
+      std::cout << "Test failed: received error is incorrect." << std::endl;
+      return 1;
+    } else {
+      std::cout << "Test passed: caught the expected error." << std::endl;
+      return 0;
+    }
+  }
+
+  std::cout << "Test passed: results are correct." << std::endl;
+  return 0;
+}