diff --git a/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java b/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java
index a2fae80a3..5ae238e9b 100644
--- a/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java
+++ b/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java
@@ -48,6 +48,7 @@ public class VariableBuilder {
 
    /**
     * Build the variable with the properties derived from type, scope, directives and configuration.
+    *
     * @return The variable
     */
    public Variable build() {
@@ -222,11 +223,15 @@ public class VariableBuilder {
     */
    public boolean isSingleStaticAssignment() {
       if(hasDirective(Directive.FormMa.class))
+         // the __ma directive forces multiple-assignment
+         return false;
+      else if(isNoModify())
+         // (volatile) no-modify variables must be load/store
+         // TODO: Change to isVolatile()!
          return false;
-      else if(!isConstant())
-         return true;
       else
-         return false;
+         // All others are single-static-assignment (by default)
+         return true;
    }
 
    /**
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
index f9f5d15f8..55b09bab8 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
@@ -266,8 +266,8 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
       String varName = ctx.NAME().getText();
       VariableBuilder varBuilder = new VariableBuilder(varName, getCurrentScope(), true, declVarType, null, declVarDirectives, currentDataSegment);
       // TODO: const parameter pointer should be no-modify!
-      if(varBuilder.hasDirective(Directive.Const.class))
-         throw new CompileError("Error! Const parameters not supported " + varName + " in " + getCurrentScope().getFullName() + "()");
+      //if(varBuilder.hasDirective(Directive.Const.class))
+      //   throw new CompileError("Error! Const parameters not supported " + varName + " in " + getCurrentScope().getFullName() + "()");
       Variable param = varBuilder.build();
       exitDeclTypes();
       return param;
diff --git a/src/test/java/dk/camelot64/kickc/test/TestPrograms.java b/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
index 76b5e32b5..cc38094e7 100644
--- a/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
+++ b/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
@@ -38,8 +38,23 @@ public class TestPrograms {
    }
 
    @Test
-   public void testNomodify0() throws IOException, URISyntaxException {
-      assertError("nomodify-0", "Constants can not be modified");
+   public void testNomodify5() throws IOException, URISyntaxException {
+      assertError("nomodify-5", "const variable may not be modified");
+   }
+
+   @Test
+   public void testNomodify4() throws IOException, URISyntaxException {
+      compileAndCompare("nomodify-4");
+   }
+
+   @Test
+   public void testNomodify3() throws IOException, URISyntaxException {
+      compileAndCompare("nomodify-3");
+   }
+
+   @Test
+   public void testNomodify2() throws IOException, URISyntaxException {
+      assertError("nomodify-2", "const variable may not be modified");
    }
 
    @Test
@@ -47,6 +62,11 @@ public class TestPrograms {
       assertError("nomodify-1", "const variable may not be modified");
    }
 
+   @Test
+   public void testNomodify0() throws IOException, URISyntaxException {
+      assertError("nomodify-0", "Constants can not be modified");
+   }
+
    @Test
    public void testConstantWithPrePost() throws IOException, URISyntaxException {
       assertError("constant-prepost", "Constant value contains a pre/post-modifier");
diff --git a/src/test/kc/nomodify-2.kc b/src/test/kc/nomodify-2.kc
new file mode 100644
index 000000000..c1ff5c37b
--- /dev/null
+++ b/src/test/kc/nomodify-2.kc
@@ -0,0 +1,6 @@
+// Test that modifying a nomodify-variable causes an error
+
+void main() {
+    const volatile char i = 7;
+    i = 8;
+}
\ No newline at end of file
diff --git a/src/test/kc/nomodify-3.kc b/src/test/kc/nomodify-3.kc
new file mode 100644
index 000000000..5cf0b389e
--- /dev/null
+++ b/src/test/kc/nomodify-3.kc
@@ -0,0 +1,9 @@
+// Test that a volatile nomodify-variable works as expected
+
+const volatile char i = 7;
+
+const char* SCREEN = 0x0400;
+
+void main() {
+    SCREEN[0] = i;
+}
\ No newline at end of file
diff --git a/src/test/kc/nomodify-4.kc b/src/test/kc/nomodify-4.kc
new file mode 100644
index 000000000..1f43268d6
--- /dev/null
+++ b/src/test/kc/nomodify-4.kc
@@ -0,0 +1,12 @@
+// Test that a nomodify parameter works
+
+void main() {
+    print('a');
+    print('b');
+}
+
+const char* SCREEN = 0x0400;
+
+void print(const char c) {
+    *SCREEN = c;
+}
\ No newline at end of file
diff --git a/src/test/kc/nomodify-5.kc b/src/test/kc/nomodify-5.kc
new file mode 100644
index 000000000..85e887c54
--- /dev/null
+++ b/src/test/kc/nomodify-5.kc
@@ -0,0 +1,12 @@
+// Test that modifying a nomodify-parameter fails as expected
+
+void main() {
+    print('a');
+    print('b');
+}
+
+const char* SCREEN = 0x0400;
+
+void print(const char c) {
+    *SCREEN = c++;
+}
\ No newline at end of file
diff --git a/src/test/ref/nomodify-3.asm b/src/test/ref/nomodify-3.asm
new file mode 100644
index 000000000..5ad589971
--- /dev/null
+++ b/src/test/ref/nomodify-3.asm
@@ -0,0 +1,16 @@
+// Test that a volatile nomodify-variable works as expected
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  .label SCREEN = $400
+  .label i = 2
+__bbegin:
+  lda #7
+  sta.z i
+  jsr main
+  rts
+main: {
+    lda.z i
+    sta SCREEN
+    rts
+}
diff --git a/src/test/ref/nomodify-3.cfg b/src/test/ref/nomodify-3.cfg
new file mode 100644
index 000000000..8754c6504
--- /dev/null
+++ b/src/test/ref/nomodify-3.cfg
@@ -0,0 +1,17 @@
+@begin: scope:[]  from
+  [0] (byte) i ← (byte) 7
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] *((const byte*) SCREEN) ← (byte) i
+  to:main::@return
+main::@return: scope:[main]  from main
+  [5] return 
+  to:@return
diff --git a/src/test/ref/nomodify-3.log b/src/test/ref/nomodify-3.log
new file mode 100644
index 000000000..76677e957
--- /dev/null
+++ b/src/test/ref/nomodify-3.log
@@ -0,0 +1,246 @@
+
+CONTROL FLOW GRAPH SSA
+@begin: scope:[]  from
+  (byte) i ← (number) 7
+  to:@1
+
+(void()) main()
+main: scope:[main]  from @1
+  *((const byte*) SCREEN + (number) 0) ← (byte) i
+  to:main::@return
+main::@return: scope:[main]  from main
+  return 
+  to:@return
+@1: scope:[]  from @begin
+  call main 
+  to:@2
+@2: scope:[]  from @1
+  to:@end
+@end: scope:[]  from @2
+
+SYMBOL TABLE SSA
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(const byte*) SCREEN = (byte*)(number) $400
+(byte) i loadstore
+(void()) main()
+(label) main::@return
+
+Adding number conversion cast (unumber) 7 in (byte) i ← (number) 7
+Adding number conversion cast (unumber) 0 in *((const byte*) SCREEN + (number) 0) ← (byte) i
+Successful SSA optimization PassNAddNumberTypeConversions
+Inlining cast (byte) i ← (unumber)(number) 7
+Successful SSA optimization Pass2InlineCast
+Simplifying constant pointer cast (byte*) 1024
+Simplifying constant integer cast 7
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (byte) 7
+Finalized unsigned number type (byte) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simplifying expression containing zero SCREEN in [1] *((const byte*) SCREEN + (byte) 0) ← (byte) i
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @2
+Adding NOP phi() at start of @end
+CALL GRAPH
+Calls in [] to main:2 
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+Culled Empty Block (label) @2
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+
+FINAL CONTROL FLOW GRAPH
+@begin: scope:[]  from
+  [0] (byte) i ← (byte) 7
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] *((const byte*) SCREEN) ← (byte) i
+  to:main::@return
+main::@return: scope:[main]  from main
+  [5] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+(byte) i loadstore 2.0
+(void()) main()
+
+Initial phi equivalence classes
+Added variable i to live range equivalence class [ i ]
+Complete equivalence classes
+[ i ]
+Allocated zp[1]:2 [ i ]
+
+INITIAL ASM
+Target platform is c64basic / MOS6502X
+  // File Comments
+// Test that a volatile nomodify-variable works as expected
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  .label i = 2
+  // @begin
+__bbegin:
+  // [0] (byte) i ← (byte) 7 -- vbuz1=vbuc1 
+  lda #7
+  sta.z i
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+main: {
+    // [4] *((const byte*) SCREEN) ← (byte) i -- _deref_pbuc1=vbuz1 
+    lda.z i
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [5] return 
+    rts
+}
+  // File Data
+
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [0] (byte) i ← (byte) 7 [ i ] (  [ i ] ) always clobbers reg byte a 
+Statement [4] *((const byte*) SCREEN) ← (byte) i [ ] ( main:2 [ ] ) always clobbers reg byte a 
+Potential registers zp[1]:2 [ i ] : zp[1]:2 , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [] 2: zp[1]:2 [ i ] 
+Uplift Scope [main] 
+
+Uplifting [] best 33 combination zp[1]:2 [ i ] 
+Uplifting [main] best 33 combination 
+Attempting to uplift remaining variables inzp[1]:2 [ i ]
+Uplifting [] best 33 combination zp[1]:2 [ i ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// Test that a volatile nomodify-variable works as expected
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  .label i = 2
+  // @begin
+__bbegin:
+  // [0] (byte) i ← (byte) 7 -- vbuz1=vbuc1 
+  lda #7
+  sta.z i
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+main: {
+    // [4] *((const byte*) SCREEN) ← (byte) i -- _deref_pbuc1=vbuz1 
+    lda.z i
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [5] return 
+    rts
+}
+  // File Data
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __b1
+Removing instruction jmp __bend
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __b1_from___bbegin:
+Removing instruction __bend_from___b1:
+Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction __b1:
+Removing instruction __bend:
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+Adding RTS to root block 
+Succesful ASM optimization Pass5AddMainRts
+
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(const byte*) SCREEN = (byte*) 1024
+(byte) i loadstore zp[1]:2 2.0
+(void()) main()
+(label) main::@return
+
+zp[1]:2 [ i ]
+
+
+FINAL ASSEMBLER
+Score: 30
+
+  // File Comments
+// Test that a volatile nomodify-variable works as expected
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  .label i = 2
+  // @begin
+__bbegin:
+  // i = 7
+  // [0] (byte) i ← (byte) 7 -- vbuz1=vbuc1 
+  lda #7
+  sta.z i
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+  // @1
+  // [2] call main 
+  jsr main
+  rts
+  // [3] phi from @1 to @end [phi:@1->@end]
+  // @end
+  // main
+main: {
+    // SCREEN[0] = i
+    // [4] *((const byte*) SCREEN) ← (byte) i -- _deref_pbuc1=vbuz1 
+    lda.z i
+    sta SCREEN
+    // main::@return
+    // }
+    // [5] return 
+    rts
+}
+  // File Data
+
diff --git a/src/test/ref/nomodify-3.sym b/src/test/ref/nomodify-3.sym
new file mode 100644
index 000000000..5cd20bd4e
--- /dev/null
+++ b/src/test/ref/nomodify-3.sym
@@ -0,0 +1,9 @@
+(label) @1
+(label) @begin
+(label) @end
+(const byte*) SCREEN = (byte*) 1024
+(byte) i loadstore zp[1]:2 2.0
+(void()) main()
+(label) main::@return
+
+zp[1]:2 [ i ]
diff --git a/src/test/ref/nomodify-4.asm b/src/test/ref/nomodify-4.asm
new file mode 100644
index 000000000..d1108d52e
--- /dev/null
+++ b/src/test/ref/nomodify-4.asm
@@ -0,0 +1,20 @@
+// Test that a nomodify parameter works
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  .label SCREEN = $400
+main: {
+    lda #'a'
+    sta.z print.c
+    jsr print
+    lda #'b'
+    sta.z print.c
+    jsr print
+    rts
+}
+print: {
+    .label c = 2
+    lda.z c
+    sta SCREEN
+    rts
+}
diff --git a/src/test/ref/nomodify-4.cfg b/src/test/ref/nomodify-4.cfg
new file mode 100644
index 000000000..b30edf60c
--- /dev/null
+++ b/src/test/ref/nomodify-4.cfg
@@ -0,0 +1,30 @@
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] (byte) print::c ← (byte) 'a'
+  [5] call print 
+  to:main::@1
+main::@1: scope:[main]  from main
+  [6] (byte) print::c ← (byte) 'b'
+  [7] call print 
+  to:main::@return
+main::@return: scope:[main]  from main::@1
+  [8] return 
+  to:@return
+
+(void()) print((byte) print::c)
+print: scope:[print]  from main main::@1
+  [9] *((const byte*) SCREEN) ← (byte) print::c
+  to:print::@return
+print::@return: scope:[print]  from print
+  [10] return 
+  to:@return
diff --git a/src/test/ref/nomodify-4.log b/src/test/ref/nomodify-4.log
new file mode 100644
index 000000000..4e27c8c55
--- /dev/null
+++ b/src/test/ref/nomodify-4.log
@@ -0,0 +1,336 @@
+Culled Empty Block (label) @1
+
+CONTROL FLOW GRAPH SSA
+@begin: scope:[]  from
+  to:@2
+
+(void()) main()
+main: scope:[main]  from @2
+  (byte) print::c ← (byte) 'a'
+  call print 
+  to:main::@1
+main::@1: scope:[main]  from main
+  (byte) print::c ← (byte) 'b'
+  call print 
+  to:main::@2
+main::@2: scope:[main]  from main::@1
+  to:main::@return
+main::@return: scope:[main]  from main::@2
+  return 
+  to:@return
+
+(void()) print((byte) print::c)
+print: scope:[print]  from main main::@1
+  *((const byte*) SCREEN) ← (byte) print::c
+  to:print::@return
+print::@return: scope:[print]  from print
+  return 
+  to:@return
+@2: scope:[]  from @begin
+  call main 
+  to:@3
+@3: scope:[]  from @2
+  to:@end
+@end: scope:[]  from @3
+
+SYMBOL TABLE SSA
+(label) @2
+(label) @3
+(label) @begin
+(label) @end
+(const byte*) SCREEN = (byte*)(number) $400
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@return
+(void()) print((byte) print::c)
+(label) print::@return
+(byte) print::c loadstore
+
+Simplifying constant pointer cast (byte*) 1024
+Successful SSA optimization PassNCastSimplification
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @2
+Adding NOP phi() at start of @3
+Adding NOP phi() at start of @end
+Adding NOP phi() at start of main::@2
+CALL GRAPH
+Calls in [] to main:2 
+Calls in [main] to print:6 print:8 
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+Culled Empty Block (label) @3
+Culled Empty Block (label) main::@2
+Renumbering block @2 to @1
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+
+FINAL CONTROL FLOW GRAPH
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] (byte) print::c ← (byte) 'a'
+  [5] call print 
+  to:main::@1
+main::@1: scope:[main]  from main
+  [6] (byte) print::c ← (byte) 'b'
+  [7] call print 
+  to:main::@return
+main::@return: scope:[main]  from main::@1
+  [8] return 
+  to:@return
+
+(void()) print((byte) print::c)
+print: scope:[print]  from main main::@1
+  [9] *((const byte*) SCREEN) ← (byte) print::c
+  to:print::@return
+print::@return: scope:[print]  from print
+  [10] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+(void()) main()
+(void()) print((byte) print::c)
+(byte) print::c loadstore 3.0
+
+Initial phi equivalence classes
+Added variable print::c to live range equivalence class [ print::c ]
+Complete equivalence classes
+[ print::c ]
+Allocated zp[1]:2 [ print::c ]
+
+INITIAL ASM
+Target platform is c64basic / MOS6502X
+  // File Comments
+// Test that a nomodify parameter works
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  // @begin
+__bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+main: {
+    // [4] (byte) print::c ← (byte) 'a' -- vbuz1=vbuc1 
+    lda #'a'
+    sta.z print.c
+    // [5] call print 
+    jsr print
+    jmp __b1
+    // main::@1
+  __b1:
+    // [6] (byte) print::c ← (byte) 'b' -- vbuz1=vbuc1 
+    lda #'b'
+    sta.z print.c
+    // [7] call print 
+    jsr print
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [8] return 
+    rts
+}
+  // print
+print: {
+    .label c = 2
+    // [9] *((const byte*) SCREEN) ← (byte) print::c -- _deref_pbuc1=vbuz1 
+    lda.z c
+    sta SCREEN
+    jmp __breturn
+    // print::@return
+  __breturn:
+    // [10] return 
+    rts
+}
+  // File Data
+
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [4] (byte) print::c ← (byte) 'a' [ print::c ] ( main:2 [ print::c ] ) always clobbers reg byte a 
+Statement [6] (byte) print::c ← (byte) 'b' [ print::c ] ( main:2 [ print::c ] ) always clobbers reg byte a 
+Statement [9] *((const byte*) SCREEN) ← (byte) print::c [ ] ( main:2::print:5 [ ] main:2::print:7 [ ] ) always clobbers reg byte a 
+Potential registers zp[1]:2 [ print::c ] : zp[1]:2 , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [print] 3: zp[1]:2 [ print::c ] 
+Uplift Scope [main] 
+Uplift Scope [] 
+
+Uplifting [print] best 62 combination zp[1]:2 [ print::c ] 
+Uplifting [main] best 62 combination 
+Uplifting [] best 62 combination 
+Attempting to uplift remaining variables inzp[1]:2 [ print::c ]
+Uplifting [print] best 62 combination zp[1]:2 [ print::c ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// Test that a nomodify parameter works
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  // @begin
+__bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+main: {
+    // [4] (byte) print::c ← (byte) 'a' -- vbuz1=vbuc1 
+    lda #'a'
+    sta.z print.c
+    // [5] call print 
+    jsr print
+    jmp __b1
+    // main::@1
+  __b1:
+    // [6] (byte) print::c ← (byte) 'b' -- vbuz1=vbuc1 
+    lda #'b'
+    sta.z print.c
+    // [7] call print 
+    jsr print
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [8] return 
+    rts
+}
+  // print
+print: {
+    .label c = 2
+    // [9] *((const byte*) SCREEN) ← (byte) print::c -- _deref_pbuc1=vbuz1 
+    lda.z c
+    sta SCREEN
+    jmp __breturn
+    // print::@return
+  __breturn:
+    // [10] return 
+    rts
+}
+  // File Data
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __b1
+Removing instruction jmp __bend
+Removing instruction jmp __b1
+Removing instruction jmp __breturn
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Replacing label __bbegin with __b1
+Removing instruction __bbegin:
+Removing instruction __b1_from___bbegin:
+Removing instruction __bend_from___b1:
+Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction __bend:
+Removing instruction __b1:
+Removing instruction __breturn:
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+Updating BasicUpstart to call main directly
+Removing instruction jsr main
+Succesful ASM optimization Pass5SkipBegin
+Removing instruction __b1:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(const byte*) SCREEN = (byte*) 1024
+(void()) main()
+(label) main::@1
+(label) main::@return
+(void()) print((byte) print::c)
+(label) print::@return
+(byte) print::c loadstore zp[1]:2 3.0
+
+zp[1]:2 [ print::c ]
+
+
+FINAL ASSEMBLER
+Score: 41
+
+  // File Comments
+// Test that a nomodify parameter works
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  // @begin
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+  // @1
+  // [2] call main 
+  // [3] phi from @1 to @end [phi:@1->@end]
+  // @end
+  // main
+main: {
+    // print('a')
+    // [4] (byte) print::c ← (byte) 'a' -- vbuz1=vbuc1 
+    lda #'a'
+    sta.z print.c
+    // [5] call print 
+    jsr print
+    // main::@1
+    // print('b')
+    // [6] (byte) print::c ← (byte) 'b' -- vbuz1=vbuc1 
+    lda #'b'
+    sta.z print.c
+    // [7] call print 
+    jsr print
+    // main::@return
+    // }
+    // [8] return 
+    rts
+}
+  // print
+print: {
+    .label c = 2
+    // *SCREEN = c
+    // [9] *((const byte*) SCREEN) ← (byte) print::c -- _deref_pbuc1=vbuz1 
+    lda.z c
+    sta SCREEN
+    // print::@return
+    // }
+    // [10] return 
+    rts
+}
+  // File Data
+
diff --git a/src/test/ref/nomodify-4.sym b/src/test/ref/nomodify-4.sym
new file mode 100644
index 000000000..49c85c25d
--- /dev/null
+++ b/src/test/ref/nomodify-4.sym
@@ -0,0 +1,12 @@
+(label) @1
+(label) @begin
+(label) @end
+(const byte*) SCREEN = (byte*) 1024
+(void()) main()
+(label) main::@1
+(label) main::@return
+(void()) print((byte) print::c)
+(label) print::@return
+(byte) print::c loadstore zp[1]:2 3.0
+
+zp[1]:2 [ print::c ]