diff --git a/src/main/java/com/sk89q/worldedit/expression/runtime/Functions.java b/src/main/java/com/sk89q/worldedit/expression/runtime/Functions.java
index 018d217ea..51d1a2f36 100644
--- a/src/main/java/com/sk89q/worldedit/expression/runtime/Functions.java
+++ b/src/main/java/com/sk89q/worldedit/expression/runtime/Functions.java
@@ -377,18 +377,23 @@ public final class Functions {
     }
 
 
-    private static double queryInternal(LValue type, LValue data, double typeId, double dataValue) throws EvaluationException {
+    private static double queryInternal(RValue type, RValue data, double typeId, double dataValue) throws EvaluationException {
         // Compare to input values and determine return value
-        final double ret = typeId == type.getValue() && typeId == type.getValue() ? 1.0 : 0.0;
+        final double ret = (typeId == type.getValue() && dataValue == data.getValue()) ? 1.0 : 0.0;
 
-        type.assign(typeId);
-        data.assign(dataValue);
+        if (type instanceof LValue) {
+            ((LValue) type).assign(typeId);
+        }
+
+        if (data instanceof LValue) {
+            ((LValue) data).assign(dataValue);
+        }
 
         return ret;
     }
 
     @Dynamic
-    public static double query(RValue x, RValue y, RValue z, LValue type, LValue data) throws EvaluationException {
+    public static double query(RValue x, RValue y, RValue z, RValue type, RValue data) throws EvaluationException {
         final double xp = x.getValue();
         final double yp = y.getValue();
         final double zp = z.getValue();
@@ -403,7 +408,7 @@ public final class Functions {
     }
 
     @Dynamic
-    public static double queryAbs(RValue x, RValue y, RValue z, LValue type, LValue data) throws EvaluationException {
+    public static double queryAbs(RValue x, RValue y, RValue z, RValue type, RValue data) throws EvaluationException {
         final double xp = x.getValue();
         final double yp = y.getValue();
         final double zp = z.getValue();
@@ -418,7 +423,7 @@ public final class Functions {
     }
 
     @Dynamic
-    public static double queryRel(RValue x, RValue y, RValue z, LValue type, LValue data) throws EvaluationException {
+    public static double queryRel(RValue x, RValue y, RValue z, RValue type, RValue data) throws EvaluationException {
         final double xp = x.getValue();
         final double yp = y.getValue();
         final double zp = z.getValue();
diff --git a/src/test/java/com/sk89q/worldedit/expression/ExpressionTest.java b/src/test/java/com/sk89q/worldedit/expression/ExpressionTest.java
index 26acd4533..ab30d0b27 100644
--- a/src/test/java/com/sk89q/worldedit/expression/ExpressionTest.java
+++ b/src/test/java/com/sk89q/worldedit/expression/ExpressionTest.java
@@ -3,6 +3,7 @@ package com.sk89q.worldedit.expression;
 import static org.junit.Assert.*;
 import static java.lang.Math.*;
 
+import com.sk89q.worldedit.expression.runtime.ExpressionEnvironment;
 import org.junit.*;
 
 import com.sk89q.worldedit.expression.lexer.LexerException;
@@ -59,6 +60,26 @@ public class ExpressionTest {
             compile("x(");
             fail("Error expected");
         } catch (ParserException e) {}
+
+        // test overloader errors
+        try {
+            compile("atan2(1)");
+            fail("Error expected");
+        } catch (ParserException e) {
+            assertEquals("Error position", 0, e.getPosition());
+        }
+        try {
+            compile("atan2(1, 2, 3)");
+            fail("Error expected");
+        } catch (ParserException e) {
+            assertEquals("Error position", 0, e.getPosition());
+        }
+        try {
+            compile("rotate(1, 2, 3)");
+            fail("Error expected");
+        } catch (ParserException e) {
+            assertEquals("Error position", 0, e.getPosition());
+        }
     }
 
     @Test
@@ -110,8 +131,52 @@ public class ExpressionTest {
         assertEquals(127, simpleEval("x=1;y=2;z=3;switch (3) { case 1: x=5; case 2: y=6; default: z=7 } x*100+y*10+z"), 0);
     }
 
+    @Test
+    public void testQuery() throws Exception {
+        assertEquals(1, simpleEval("a=1;b=2;query(3,4,5,a,b); a==3 && b==4"), 0);
+        assertEquals(1, simpleEval("a=1;b=2;queryAbs(3,4,5,a*1,b*1); a==1 && b==2"), 0);
+        assertEquals(1, simpleEval("a=1;b=2;queryRel(3,4,5,(a),(b)); a==300 && b==400"), 0);
+        assertEquals(1, simpleEval("query(3,4,5,3,4)"), 0);
+        assertEquals(1, simpleEval("!query(3,4,5,3,2)"), 0);
+        assertEquals(1, simpleEval("!queryAbs(3,4,5,10,40)"), 0);
+        assertEquals(1, simpleEval("!queryRel(3,4,5,100,200)"), 0);
+    }
+
     private double simpleEval(String expressionString) throws ExpressionException {
         final Expression expression = compile(expressionString);
+
+        expression.setEnvironment(new ExpressionEnvironment() {
+            @Override
+            public int getBlockType(double x, double y, double z) {
+                return (int) x;
+            }
+
+            @Override
+            public int getBlockData(double x, double y, double z) {
+                return (int) y;
+            }
+
+            @Override
+            public int getBlockTypeAbs(double x, double y, double z) {
+                return (int) x*10;
+            }
+
+            @Override
+            public int getBlockDataAbs(double x, double y, double z) {
+                return (int) y*10;
+            }
+
+            @Override
+            public int getBlockTypeRel(double x, double y, double z) {
+                return (int) x*100;
+            }
+
+            @Override
+            public int getBlockDataRel(double x, double y, double z) {
+                return (int) y*100;
+            }
+        });
+
         return expression.evaluate();
     }