diff --git a/firmware/gen_signature.sh b/firmware/gen_signature.sh
index e25a33cca3..58acebabdb 100644
--- a/firmware/gen_signature.sh
+++ b/firmware/gen_signature.sh
@@ -9,11 +9,7 @@ date=$(date +"%Y.%m.%d")
 echo "#define SIGNATURE_DATE $date" > tunerstudio/signature_${SHORT_BOARDNAME}.txt
 echo "#define SIGNATURE_BOARD ${SHORT_BOARDNAME}" >> tunerstudio/signature_${SHORT_BOARDNAME}.txt
 
-nanosec=$(date +"%N")
-# prevent octal numbers once and for all
-nanosec="1$nanosec"
-hash=$(($nanosec % 2147483648))
-echo "#define SIGNATURE_HASH $hash" >> tunerstudio/signature_${SHORT_BOARDNAME}.txt
+echo "// SIGNATURE_HASH is a built-in variable generated by ConfigDefinition.jar" >> tunerstudio/signature_${SHORT_BOARDNAME}.txt
 
 echo "#define TS_SIGNATURE \"rusEFI @@SIGNATURE_DATE@@.@@SIGNATURE_BOARD@@.@@SIGNATURE_HASH@@\"" >> tunerstudio/signature_${SHORT_BOARDNAME}.txt
 
diff --git a/java_tools/configuration_definition/src/com/rusefi/ConfigDefinition.java b/java_tools/configuration_definition/src/com/rusefi/ConfigDefinition.java
index 8df02608be..9331d99b89 100644
--- a/java_tools/configuration_definition/src/com/rusefi/ConfigDefinition.java
+++ b/java_tools/configuration_definition/src/com/rusefi/ConfigDefinition.java
@@ -18,6 +18,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
+import java.util.zip.CRC32;
 
 /**
  * Andrey Belomutskiy, (c) 2013-2020
@@ -169,6 +170,9 @@ public class ConfigDefinition {
         boolean needToUpdateTsFiles = false;
         if (tsPath != null) {
             inputAllFiles.add(TSProjectConsumer.getTsFileInputName(tsPath));
+        }
+
+        if (tsPath != null) {
             SystemOut.println("Check the input/output TS files:");
             needToUpdateTsFiles = checkIfOutputFilesAreOutdated(inputAllFiles, cachePath, cacheZipFile);
         }
@@ -180,6 +184,17 @@ public class ConfigDefinition {
             return;
         }
 
+        // get CRC32 of given input files
+        long crc32 = 0;
+        for (String iFile : inputAllFiles) {
+            long c = getCrc32(iFile) & 0xffffffffL;
+            SystemOut.println("CRC32 from " + iFile + " = " + c);
+            crc32 ^= c;
+        }
+        SystemOut.println("CRC32 from all input files = " + crc32);
+        // store the CRC32 as a built-in variable
+        VariableRegistry.INSTANCE.register("SIGNATURE_HASH", "" + crc32);
+
         if (firingEnumFileName != null) {
             SystemOut.println("Reading firing from " + firingEnumFileName);
             VariableRegistry.INSTANCE.register("FIRINGORDER", FiringOrderTSLogic.invoke(firingEnumFileName));
@@ -210,6 +225,8 @@ public class ConfigDefinition {
             destinations.add(new TSProjectConsumer(tsWriter, tsPath, state));
 
             VariableRegistry tmpRegistry = new VariableRegistry();
+            // store the CRC32 as a built-in variable
+            tmpRegistry.register("SIGNATURE_HASH", "" + crc32);
             readPrependValues(tmpRegistry, signaturePrependFile);
             destinations.add(new SignatureConsumer(signatureDestination, tmpRegistry));
         }
@@ -440,4 +457,18 @@ public class ConfigDefinition {
     private static String getCachedInputFileName(String inputFile, String cachePath) {
         return cachePath + File.separator + inputFile;
     }
+
+    private static long getCrc32(String fileName) throws IOException {
+        File file = new File(fileName);
+        byte[] f1 = Files.readAllBytes(file.toPath());
+        CRC32 c = new CRC32();
+        c.update(f1, 0, f1.length);
+        return c.getValue();
+    }
+
+    private static void deleteFile(String fileName) throws IOException {
+        File file = new File(fileName);
+        // todo: validate?
+        file.delete();
+    }
 }