diff --git a/generator/src/main/java/bwmirror/generator/JavaContext.java b/generator/src/main/java/bwmirror/generator/JavaContext.java
index e197451..0e6faad 100644
--- a/generator/src/main/java/bwmirror/generator/JavaContext.java
+++ b/generator/src/main/java/bwmirror/generator/JavaContext.java
@@ -1,11 +1,13 @@
 package bwmirror.generator;
 
+import bwmirror.c.Param;
 import bwmirror.util.Generic;
 import bwmirror.util.PointerTest;
 
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Created with IntelliJ IDEA.
@@ -29,6 +31,8 @@ public class JavaContext {
 
     private List<String> selfReturnTypes = Arrays.asList("BWTA::Polygon");
 
+    private Map<String, Param> requiresExplicitDummyPredicate = new HashMap<>();
+
 
     private String packageName = "bwapi";
 
@@ -39,6 +43,8 @@ public class JavaContext {
         javaToCType.put("void", "void");
         javaToCType.put("boolean", "jboolean");
         javaToCType.put("String", "jstring");
+
+        requiresExplicitDummyPredicate.put("getUnitsInWeaponRange", new Param("", "IdentityUnitFilter"));
     }
 
     public boolean isSelfReturnType(String clsName, String methodName) {
@@ -93,6 +99,10 @@ public class JavaContext {
         return constantTypes.contains(javaType);
     }
 
+    public boolean needsExtraFilterParameter(String methodName) { return requiresExplicitDummyPredicate.containsKey(methodName); }
+
+    public Param getExtraFilterParameter(String methodName) { return requiresExplicitDummyPredicate.get(methodName); }
+
     public String ptrCType() {
         return "jobject";
     }
diff --git a/generator/src/main/java/bwmirror/generator/ccalls/CallImplementer.java b/generator/src/main/java/bwmirror/generator/ccalls/CallImplementer.java
index 5d106c8..71432f4 100644
--- a/generator/src/main/java/bwmirror/generator/ccalls/CallImplementer.java
+++ b/generator/src/main/java/bwmirror/generator/ccalls/CallImplementer.java
@@ -60,7 +60,12 @@ public class CallImplementer {
                 "#include <jni.h>\n" +
                 "#include <cstring>\n" +
                 "\n" +
-                "using namespace BWAPI;\n\n");
+                "using namespace BWAPI;\n\n" +
+                "\n" +
+                "bool IdentityUnitFilter(Unit u) {\n" +
+                "\treturn true;\n" +
+                "}\n" +
+                "\n");
     }
 
     private void implementAccessObject(String clsName, String objName) {
@@ -505,6 +510,8 @@ public class CallImplementer {
             String genericType = convertToBWTA(Generic.extractGeneric(javaRetType));
             if (javaPackageName.equals("bwta") || (!genericType.equals("UnitType") && !genericType.equals("Position") && !genericType.equals("TilePosition"))){
                 out.print(wrapInCCollection(genericType, javaMethodName) + " cresult = " + objectAccessor + (javaContext.isSelfReturnType(clsName, javaMethodName) ? "" : javaMethodName + "("));
+                if (javaContext.needsExtraFilterParameter(javaMethodName))
+                    params.add(javaContext.getExtraFilterParameter(javaMethodName));
                 implementRealParams(params);
                 if (!javaContext.isSelfReturnType(clsName, javaMethodName)) {
                     out.print(")");