diff --git a/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java b/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java
index a916acb28933..55326effd5de 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java
@@ -504,7 +504,10 @@ public class JavaBuilder extends ModuleLevelBuilder {
     //final JpsJavaCompilerConfiguration config = JpsJavaExtensionService.getInstance().getOrCreateCompilerConfiguration(project);
     //final JpsJavaCompilerOptions options = config.getCurrentCompilerOptions();
     //return options.MAXIMUM_HEAP_SIZE;
-    final int maxMbytes = (int)Runtime.getRuntime().maxMemory() / 1048576;
+    final int maxMbytes = (int)(Runtime.getRuntime().maxMemory() / 1048576L);
+    if (maxMbytes < 0) {
+      return -1; // in case of int overflow, return -1 to let VM choose the heap size
+    }
     return Math.max(maxMbytes * 75 / 100, 256); // minimum 256 Mb, maximum 75% from JPS max heap size 
   }