diff --git a/java_tools/configuration_definition_base/src/main/java/com/rusefi/ReaderStateImpl.java b/java_tools/configuration_definition_base/src/main/java/com/rusefi/ReaderStateImpl.java
index 4c54c780bd..56c8a08ea3 100644
--- a/java_tools/configuration_definition_base/src/main/java/com/rusefi/ReaderStateImpl.java
+++ b/java_tools/configuration_definition_base/src/main/java/com/rusefi/ReaderStateImpl.java
@@ -3,8 +3,10 @@ package com.rusefi;
 import com.devexperts.logging.Logging;
 import com.opensr5.ini.RawIniFile;
 import com.opensr5.ini.field.EnumIniField;
+import com.rusefi.core.Pair;
 import com.rusefi.enum_reader.Value;
 import com.rusefi.output.*;
+import com.rusefi.parse.TokenUtil;
 import com.rusefi.parse.TypesHelper;
 import com.rusefi.util.LazyFile;
 import com.rusefi.util.SystemOut;
@@ -146,20 +148,20 @@ public class ReaderStateImpl implements ReaderState {
     }
 
     private void handleCustomLine(String customLineWithPrefix) {
-        String line = customLineWithPrefix.substring(CUSTOM.length() + 1).trim();
-        int index = line.indexOf(' ');
-        String name = line.substring(0, index);
+        String withoutPrefix = customLineWithPrefix.substring(CUSTOM.length() + 1).trim();
+        Pair<String, String> nameAndRest = TokenUtil.grabFirstTokenAndTheRest(withoutPrefix);
+        String name = nameAndRest.first;
 
         String autoEnumOptions = variableRegistry.getEnumOptionsForTunerStudio(enumsReader, name);
         if (autoEnumOptions != null) {
             variableRegistry.register(name + VariableRegistry.AUTO_ENUM_SUFFIX, autoEnumOptions);
         }
 
-        line = line.substring(index).trim();
-        index = line.indexOf(' ');
-        String customSize = line.substring(0, index);
+        String line = nameAndRest.second;
+        Pair<String, String> sizeAndRest = TokenUtil.grabFirstTokenAndTheRest(line);
+        String customSize = sizeAndRest.first;
 
-        String tunerStudioLine = line.substring(index).trim();
+        String tunerStudioLine = sizeAndRest.second;
         tunerStudioLine = variableRegistry.applyVariables(tunerStudioLine);
         int size = parseSize(customSize, line);
         tsCustomSize.put(name, size);
diff --git a/java_tools/configuration_definition_base/src/main/java/com/rusefi/parse/TokenUtil.java b/java_tools/configuration_definition_base/src/main/java/com/rusefi/parse/TokenUtil.java
new file mode 100644
index 0000000000..a1bfb3c8e0
--- /dev/null
+++ b/java_tools/configuration_definition_base/src/main/java/com/rusefi/parse/TokenUtil.java
@@ -0,0 +1,21 @@
+package com.rusefi.parse;
+
+import com.rusefi.core.Pair;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class TokenUtil {
+    private static final Pattern pattern = Pattern.compile("\\s");
+
+    public static Pair<String, String> grabFirstTokenAndTheRest(String line) {
+        Matcher matcher = pattern.matcher(line);
+        if (!matcher.find())
+            throw new IllegalStateException("whitespace expected in [" + line + "]");
+        int index = matcher.start();
+        String first = line.substring(0, index);
+
+        String second = line.substring(index).trim();
+        return new Pair<>(first, second);
+    }
+}
diff --git a/java_tools/configuration_definition_base/src/test/java/com/rusefi/parse/TokenUtilTest.java b/java_tools/configuration_definition_base/src/test/java/com/rusefi/parse/TokenUtilTest.java
new file mode 100644
index 0000000000..da598547c2
--- /dev/null
+++ b/java_tools/configuration_definition_base/src/test/java/com/rusefi/parse/TokenUtilTest.java
@@ -0,0 +1,14 @@
+package com.rusefi.parse;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class TokenUtilTest {
+    @Test
+    public void test() {
+        assertEquals("first", TokenUtil.grabFirstTokenAndTheRest("first s").first);
+        assertEquals("second", TokenUtil.grabFirstTokenAndTheRest("f second \t").second);
+        assertEquals("second", TokenUtil.grabFirstTokenAndTheRest("f\tsecond\t ").second);
+    }
+}