diff --git a/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt b/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt
index 09bfebc13..f351e7c78 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt
@@ -218,15 +218,13 @@ class AstPreprocessor(val program: Program,
         val namesInSub = symbolsInSub.map{ it.first }.toSet()
         if(subroutine.asmAddress==null) {
             if(!subroutine.isAsmSubroutine && subroutine.parameters.isNotEmpty()) {
-                val vars = subroutine.statements.asSequence().filterIsInstance<VarDecl>().map { it.name }.toSet()
-                if(!vars.containsAll(subroutine.parameters.map{it.name})) {
-                    return subroutine.parameters
-                        .filter { it.name !in namesInSub }
-                        .map {
-                            val vardecl = VarDecl.fromParameter(it)
-                            IAstModification.InsertFirst(vardecl, subroutine)
-                        }
-                }
+                val existingVars = subroutine.statements.asSequence().filterIsInstance<VarDecl>().map { it.name }.toSet()
+                return subroutine.parameters
+                    .filter { it.name !in namesInSub && it.name !in existingVars }
+                    .map {
+                        val vardecl = VarDecl.fromParameter(it)
+                        IAstModification.InsertFirst(vardecl, subroutine)
+                    }
             }
         }
 
diff --git a/compilerAst/src/prog8/ast/AstToSourceTextConverter.kt b/compilerAst/src/prog8/ast/AstToSourceTextConverter.kt
index ecba0fb95..7dc9c5477 100644
--- a/compilerAst/src/prog8/ast/AstToSourceTextConverter.kt
+++ b/compilerAst/src/prog8/ast/AstToSourceTextConverter.kt
@@ -41,6 +41,10 @@ class AstToSourceTextConverter(val output: (text: String) -> Unit, val program:
     }
 
     override fun visit(block: Block) {
+        if(block.isInLibrary && skipLibraries) {
+            outputln("; library block skipped: ${block.name}")
+            return
+        }
         val addr = if(block.address!=null) block.address.toHex() else ""
         outputln("${block.name} $addr {")
         scopelevel++
@@ -527,4 +531,8 @@ class AstToSourceTextConverter(val output: (text: String) -> Unit, val program:
             whenChoice.statements.accept(this)
         outputln("")
     }
+
+    override fun visit(alias: Alias) {
+        output("alias ${alias.alias} = ${alias.target.nameInSource.joinToString(".")}")
+    }
 }
diff --git a/examples/test.p8 b/examples/test.p8
index 8def12622..559b7d347 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -2,35 +2,9 @@
 %zeropage basicsafe
 
 main {
+    alias print = txt.print_ub
+
     sub start() {
-        foo(42)
-        bar(9999,55)
-        txt.nl()
-        test(1,2,3)
-        test2(1)
-    }
-
-    sub foo(ubyte arg) {
-        txt.print_ub(arg)
-        txt.nl()
-    }
-
-    sub bar(uword arg, ubyte arg2) {
-        txt.print_uw(arg)
-        txt.spc()
-        txt.print_ub(arg2)
-        txt.nl()
-    }
-
-    asmsub test(ubyte a1 @R1, ubyte a2 @R1, ubyte a3 @R2) {      ; TODO should give register reuse error
-        %asm {{
-            rts
-        }}
-    }
-
-    asmsub test2(uword a1 @AY) clobbers(A, X) -> ubyte @X {
-        %asm {{
-            rts
-        }}
+        print(42)
     }
 }
diff --git a/syntax-files/IDEA/Prog8.xml b/syntax-files/IDEA/Prog8.xml
index a9cc8bbb3..4c8689b12 100644
--- a/syntax-files/IDEA/Prog8.xml
+++ b/syntax-files/IDEA/Prog8.xml
@@ -11,7 +11,7 @@
       <option name="HAS_PARENS" value="true" />
       <option name="HAS_STRING_ESCAPES" value="true" />
     </options>
-    <keywords keywords="&amp;;-&gt;;@;and;as;asmsub;break;clobbers;continue;do;downto;else;extsub;false;for;goto;if;if_cc;if_cs;if_eq;if_mi;if_ne;if_neg;if_nz;if_pl;if_pos;if_vc;if_vs;if_z;in;inline;not;or;repeat;return;step;sub;to;true;unroll;until;when;while;xor;~" ignore_case="false" />
+    <keywords keywords="&amp;;-&gt;;@;alias;and;as;asmsub;break;clobbers;continue;do;downto;else;extsub;false;for;goto;if;if_cc;if_cs;if_eq;if_mi;if_ne;if_neg;if_nz;if_pl;if_pos;if_vc;if_vs;if_z;in;inline;not;or;repeat;return;step;sub;to;true;unroll;until;when;while;xor;~" ignore_case="false" />
     <keywords2 keywords="%address;%align;%asm;%asmbinary;%asminclude;%breakpoint;%encoding;%import;%ir;%launcher;%memtop;%option;%output;%zeropage;%zpallowed;%zpreserved;@align64;@alignpage;@alignword;@bank;@dirty;@nozp;@requirezp;@shared;@split;@zp;atascii:;cp437:;default:;iso16:;iso5:;iso:;kata:;petscii:;sc:" />
     <keywords3 keywords="bool;byte;const;float;long;str;ubyte;uword;void;word" />
     <keywords4 keywords="abs;bankof;call;callfar;callfar2;clamp;cmp;defer;divmod;len;lsb;max;memory;min;mkword;msb;peek;peekf;peekw;poke;pokef;pokew;rol;rol2;ror;ror2;rrestore;rrestorex;rsave;rsavex;setlsb;setmsb;sgn;sizeof;sqrt" />
diff --git a/syntax-files/NotepadPlusPlus/Prog8.xml b/syntax-files/NotepadPlusPlus/Prog8.xml
index 9f13b3978..d52a00e13 100644
--- a/syntax-files/NotepadPlusPlus/Prog8.xml
+++ b/syntax-files/NotepadPlusPlus/Prog8.xml
@@ -27,7 +27,7 @@
             <Keywords name="Keywords1">void const&#x000D;&#x000A;str&#x000D;&#x000A;byte ubyte bool&#x000D;&#x000A;long word uword&#x000D;&#x000A;float&#x000D;&#x000A;zp shared split requirezp nozp</Keywords>
             <Keywords name="Keywords2">%address&#x000D;&#x000A;%asm&#x000D;&#x000A;%ir&#x000D;&#x000A;%asmbinary&#x000D;&#x000A;%asminclude&#x000D;&#x000A;%align&#x000D;&#x000A;%breakpoint&#x000D;&#x000A;%encoding&#x000D;&#x000A;%import&#x000D;&#x000A;%memtop&#x000D;&#x000A;%launcher&#x000D;&#x000A;%option&#x000D;&#x000A;%output&#x000D;&#x000A;%zeropage&#x000D;&#x000A;%zpreserved&#x000D;&#x000A;%zpallowed</Keywords>
             <Keywords name="Keywords3">inline sub asmsub extsub&#x000D;&#x000A;clobbers&#x000D;&#x000A;asm&#x000D;&#x000A;if&#x000D;&#x000A;when else&#x000D;&#x000A;if_cc if_cs if_eq if_mi if_neg if_nz if_pl if_pos if_vc if_vs if_z&#x000D;&#x000A;for in step do while repeat unroll&#x000D;&#x000A;break continue return goto</Keywords>
-            <Keywords name="Keywords4">abs call callfar callfar2 clamp cmp defer divmod len lsb lsl lsr memory mkword min max msb bankof peek peekw peekf poke pokew pokef rsave rsavex rrestore rrestorex rnd rndw rol rol2 ror ror2 setlsb setmsb sgn sizeof sqrtw</Keywords>
+            <Keywords name="Keywords4">alias abs call callfar callfar2 clamp cmp defer divmod len lsb lsl lsr memory mkword min max msb bankof peek peekw peekf poke pokew pokef rsave rsavex rrestore rrestorex rnd rndw rol rol2 ror ror2 setlsb setmsb sgn sizeof sqrtw</Keywords>
             <Keywords name="Keywords5">true false&#x000D;&#x000A;not and or xor&#x000D;&#x000A;as to downto |&gt;</Keywords>
             <Keywords name="Keywords6"></Keywords>
             <Keywords name="Keywords7"></Keywords>
diff --git a/syntax-files/SublimeText/Prog8.sublime-syntax b/syntax-files/SublimeText/Prog8.sublime-syntax
index e9679e182..1899d9865 100644
--- a/syntax-files/SublimeText/Prog8.sublime-syntax
+++ b/syntax-files/SublimeText/Prog8.sublime-syntax
@@ -117,7 +117,7 @@ contexts:
   general__5:
     - include: general
   keywords:
-    - match: (\b(sub|if|if_cs|if_cc|if_eq|if_ne|if_pl|if_mi|if_vs|if_vc|if_z|if_nz|if_pos|if_neg|for|in|to|step|do|while|until|repeat|else|when|return|break|as|goto|asmsub|clobbers)\b)
+    - match: (\b(sub|if|if_cs|if_cc|if_eq|if_ne|if_pl|if_mi|if_vs|if_vc|if_z|if_nz|if_pos|if_neg|for|in|to|step|do|while|until|repeat|else|when|return|break|as|goto|asmsub|clobbers|alias)\b)
       scope: keyword.control.prog8
     - match: (\b(and|or)\b)
       scope: keyword.operator.prog8
diff --git a/syntax-files/Vim/prog8_builtins.vim b/syntax-files/Vim/prog8_builtins.vim
index 45fbd9664..42c94a8b0 100644
--- a/syntax-files/Vim/prog8_builtins.vim
+++ b/syntax-files/Vim/prog8_builtins.vim
@@ -15,7 +15,7 @@ syn keyword prog8BuiltInFunc len
 " Miscellaneous functions
 syn keyword prog8BuiltInFunc cmp divmod lsb msb bankof mkword min max peek peekw peekf poke pokew pokef rsave rsavex rrestore rrestorex
 syn keyword prog8BuiltInFunc rol rol2 ror ror2 sizeof setlsb setmsb
-syn keyword prog8BuiltInFunc memory call callfar callfar2 clamp defer
+syn keyword prog8BuiltInFunc memory call callfar callfar2 clamp defer alias
 
 
 " c64/floats.p8