diff --git a/sycl-jit/jit-compiler/lib/rtc/DeviceCompilation.cpp b/sycl-jit/jit-compiler/lib/rtc/DeviceCompilation.cpp
index 0f59cdf572f33..c2bc9778036ca 100644
--- a/sycl-jit/jit-compiler/lib/rtc/DeviceCompilation.cpp
+++ b/sycl-jit/jit-compiler/lib/rtc/DeviceCompilation.cpp
@@ -66,38 +66,6 @@ using namespace jit_compiler;
 
 namespace {
 
-class HashPreprocessedAction : public PreprocessorFrontendAction {
-protected:
-  void ExecuteAction() override {
-    CompilerInstance &CI = getCompilerInstance();
-
-    std::string PreprocessedSource;
-    raw_string_ostream PreprocessStream(PreprocessedSource);
-
-    PreprocessorOutputOptions Opts;
-    Opts.ShowCPP = 1;
-    Opts.MinimizeWhitespace = 1;
-    // Make cache key insensitive to virtual source file and header locations.
-    Opts.ShowLineMarkers = 0;
-
-    DoPrintPreprocessedInput(CI.getPreprocessor(), &PreprocessStream, Opts);
-
-    Hash = BLAKE3::hash(arrayRefFromStringRef(PreprocessedSource));
-    Executed = true;
-  }
-
-public:
-  BLAKE3Result<> takeHash() {
-    assert(Executed);
-    Executed = false;
-    return std::move(Hash);
-  }
-
-private:
-  BLAKE3Result<> Hash;
-  bool Executed = false;
-};
-
 class SYCLToolchain {
   SYCLToolchain() {
     using namespace jit_compiler::resource;
@@ -318,28 +286,54 @@ Expected<std::string> jit_compiler::calculateHash(
   std::vector<std::string> CommandLine =
       createCommandLine(UserArgList, Format, SourceFile.Path);
 
-  HashPreprocessedAction HashAction;
+  class HashPreprocessedAction : public PreprocessorFrontendAction {
+  protected:
+    void ExecuteAction() override {
+      CompilerInstance &CI = getCompilerInstance();
 
-  if (SYCLToolchain::instance().run(CommandLine, HashAction,
-                                    getInMemoryFS(SourceFile, IncludeFiles))) {
-    BLAKE3Result<> SourceHash = HashAction.takeHash();
-    // Last argument is the source file in the format `rtc_N.cpp` which is
-    // unique for each query, so drop it:
-    CommandLine.pop_back();
+      std::string PreprocessedSource;
+      raw_string_ostream PreprocessStream(PreprocessedSource);
 
-    // TODO: Include hash of the current libsycl-jit.so/.dll somehow...
-    BLAKE3Result<> CommandLineHash =
-        BLAKE3::hash(arrayRefFromStringRef(join(CommandLine, ",")));
+      PreprocessorOutputOptions Opts;
+      Opts.ShowCPP = 1;
+      Opts.MinimizeWhitespace = 1;
+      // Make cache key insensitive to virtual source file and header locations.
+      Opts.ShowLineMarkers = 0;
 
-    std::string EncodedHash =
-        encodeBase64(SourceHash) + encodeBase64(CommandLineHash);
-    // Make the encoding filesystem-friendly.
-    std::replace(EncodedHash.begin(), EncodedHash.end(), '/', '-');
-    return std::move(EncodedHash);
+      DoPrintPreprocessedInput(CI.getPreprocessor(), &PreprocessStream, Opts);
 
-  } else {
+      Hasher.update(PreprocessedSource);
+    }
+
+  public:
+    HashPreprocessedAction(BLAKE3 &Hasher) : Hasher(Hasher) {}
+
+  private:
+    BLAKE3 &Hasher;
+  };
+
+  BLAKE3 Hasher;
+  HashPreprocessedAction HashAction{Hasher};
+
+  if (!SYCLToolchain::instance().run(CommandLine, HashAction,
+                                     getInMemoryFS(SourceFile, IncludeFiles)))
     return createStringError("Calculating source hash failed");
-  }
+
+  Hasher.update(CLANG_VERSION_STRING);
+  Hasher.update(
+      ArrayRef<uint8_t>{reinterpret_cast<const uint8_t *>(&Format),
+                        reinterpret_cast<const uint8_t *>(&Format + 1)});
+
+  // Last argument is "rtc_N.cpp" source file name which is never the same,
+  // ignore it:
+  for (auto &Opt : drop_end(CommandLine, 1))
+    Hasher.update(Opt);
+
+  std::string EncodedHash = encodeBase64(Hasher.result());
+
+  // Make the encoding filesystem-friendly.
+  std::replace(EncodedHash.begin(), EncodedHash.end(), '/', '-');
+  return std::move(EncodedHash);
 }
 
 Expected<ModuleUPtr> jit_compiler::compileDeviceCode(