diff --git a/src/main/java/org/sablecc/sablecc/parser/Parser.java b/src/main/java/org/sablecc/sablecc/parser/Parser.java
index edc50fa39be5b66f252cca7824f27c791dae25d0..9cf150b4f6de129dce4c195beeb35152b15275a1 100644
--- a/src/main/java/org/sablecc/sablecc/parser/Parser.java
+++ b/src/main/java/org/sablecc/sablecc/parser/Parser.java
@@ -71,16 +71,9 @@ public class Parser implements IParser
             }
         }
 
-        if (!(elementToCheck instanceof PositionedNode)) {
-            throw new Error(
-                "Unexpected elementToCheck (not instanceof PositionedNode): "
-                    + elementToCheck.getClass().getSimpleName() + "/"
-                    + elementToCheck);
-        }
-
-        if (!this.getMapping().containsKey(elementToCheck) || slurp ) {
-            final PositionedNode node = (PositionedNode) elementToCheck;
+        final PositionedNode node = (PositionedNode) elementToCheck;
 
+        if (!this.getMapping().containsKey(node) || slurp ) {
             // dealing with a one-token element
             if (this.lastPopped == null) {
                 this.lastPopped = this.firstPopped;
diff --git a/src/main/resources/org/sablecc/sablecc/parser.txt b/src/main/resources/org/sablecc/sablecc/parser.txt
index e5596f940f82fdbd981c5d61424a8935c7587330..65db0e6ed3c3f113ab3da6522e475571b649c1c2 100644
--- a/src/main/resources/org/sablecc/sablecc/parser.txt
+++ b/src/main/resources/org/sablecc/sablecc/parser.txt
@@ -79,16 +79,9 @@ public class Parser implements IParser
             }
         }
 
-        if (!(elementToCheck instanceof PositionedNode)) {
-            throw new Error(
-                "Unexpected elementToCheck (not instanceof PositionedNode): "
-                    + elementToCheck.getClass().getSimpleName() + "/"
-                    + elementToCheck);
-        }
-
-        if (!this.getMapping().containsKey(elementToCheck) || slurp ) {
-            final PositionedNode node = (PositionedNode) elementToCheck;
+        final PositionedNode node = (PositionedNode) elementToCheck;
 
+        if (!this.getMapping().containsKey(node) || slurp ) {
             // dealing with a one-token element
             if (this.lastPopped == null) {
                 this.lastPopped = this.firstPopped;