diff --git a/Changes b/Changes
index 8775fbe6e..c16748deb 100644
--- a/Changes
+++ b/Changes
@@ -3,6 +3,11 @@ Revision history for Verilator
 The contributors that suggested a given feature are shown in [].  [by ...]
 indicates the contributor was also the author of the fix; Thanks!
 
+* Verilator 3.881 devel
+
+****  Internal Verilation-time performance enhancements, bug1021. [Johan Bjork]
+
+
 * Verilator 3.880 2015-12-19
 
 ***   Support display %u, %v, %p, %z, bug989. [Johan Bjork]
diff --git a/src/astgen b/src/astgen
index 33bfcca3f..8aba5b352 100755
--- a/src/astgen
+++ b/src/astgen
@@ -248,8 +248,15 @@ sub write_impl {
     my $fh = open_file(@_);
     foreach my $type (sort (keys %Classes)) {
 	next if $type eq "Node";	# Special, just a return (this);
-	printf $fh "inline Ast%-16s AstNode::cast${type}() { return (dynamic_cast<Ast${type}*>(this)); }\n"
-	    ,$type."*";
+	# For performance, prefer static_cast where we can
+	if (children_of($type)) {
+	    printf $fh "inline Ast%-16s AstNode::cast${type}() { return (dynamic_cast<Ast${type}*>(this)); }\n"
+		,$type."*";
+	} else {
+	    my $ucType = uc $type;
+	    printf $fh "inline Ast%-16s AstNode::cast${type}() { return (this && this->type() == AstType::at${ucType}) ? static_cast<Ast${type}*>(this) : NULL; }\n"
+		,$type."*";
+	}
     }
     $fh->close();
 }