diff --git a/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentSignature.java b/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentSignature.java
index 147b2842d..911d71aae 100644
--- a/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentSignature.java
+++ b/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentSignature.java
@@ -218,8 +218,9 @@ public class AsmFragmentSignature {
       // Find value if it is already bound
       for (String name : bindings.keySet()) {
          Value bound = bindings.get(name);
-         if (bound.equals(value))
+         if (bound.equals(value)) {
             return name;
+         }
       }
 
       if (value instanceof Variable) {
@@ -231,19 +232,57 @@ public class AsmFragmentSignature {
             if (bound instanceof Variable) {
                Registers.Register boundRegister = ((Variable) bound).getAllocation();
                if (boundRegister != null && boundRegister.equals(register)) {
-                  return name;
+                  if (SymbolTypeInference.typeMatch(((Variable) bound).getType(), variable.getType())) {
+                     return name;
+                  }
                }
             }
          }
          // Create a new suitable name
          if (Registers.RegisterType.ZP_BYTE.equals(register.getType())) {
-            String name = "zpby" + nextZpByteIdx++;
-            bindings.put(name, value);
-            return name;
-         } else if (Registers.RegisterType.ZP_SBYTE.equals(register.getType())) {
-            String name = "zpsby" + nextZpSByteIdx++;
-            bindings.put(name, value);
-            return name;
+            SymbolType varType = ((Variable) value).getType();
+            if (SymbolType.isByte(varType)) {
+               String name = "zpby" + nextZpByteIdx++;
+               bindings.put(name, value);
+               return name;
+            } else if (SymbolType.isSByte(varType)) {
+               String name = "zpsby" + nextZpSByteIdx++;
+               bindings.put(name, value);
+               return name;
+            }
+         } else if (Registers.RegisterType.REG_X_BYTE.equals(register.getType())) {
+            SymbolType varType = ((Variable) value).getType();
+            if (SymbolType.isByte(varType)) {
+               String name = "xby";
+               bindings.put(name, value);
+               return name;
+            } else if (SymbolType.isSByte(varType)) {
+               String name = "xsby";
+               bindings.put(name, value);
+               return name;
+            }
+         } else if (Registers.RegisterType.REG_Y_BYTE.equals(register.getType())) {
+            SymbolType varType = ((Variable) value).getType();
+            if (SymbolType.isByte(varType)) {
+               String name = "yby";
+               bindings.put(name, value);
+               return name;
+            } else if (SymbolType.isSByte(varType)) {
+               String name = "ysby";
+               bindings.put(name, value);
+               return name;
+            }
+         } else if (Registers.RegisterType.REG_A_BYTE.equals(register.getType())) {
+            SymbolType varType = ((Variable) value).getType();
+            if (SymbolType.isByte(varType)) {
+               String name = "aby";
+               bindings.put(name, value);
+               return name;
+            } else if (SymbolType.isSByte(varType)) {
+               String name = "asby";
+               bindings.put(name, value);
+               return name;
+            }
          } else if (Registers.RegisterType.ZP_WORD.equals(register.getType())) {
             String name = "zpwo" + nextZpWordIdx++;
             bindings.put(name, value);
@@ -252,30 +291,6 @@ public class AsmFragmentSignature {
             String name = "zpbo" + nextZpBoolIdx++;
             bindings.put(name, value);
             return name;
-         } else if (Registers.RegisterType.REG_X_BYTE.equals(register.getType())) {
-            String name = "xby";
-            bindings.put(name, value);
-            return name;
-         } else if (Registers.RegisterType.REG_Y_BYTE.equals(register.getType())) {
-            String name = "yby";
-            bindings.put(name, value);
-            return name;
-         } else if (Registers.RegisterType.REG_A_BYTE.equals(register.getType())) {
-            String name = "aby";
-            bindings.put(name, value);
-            return name;
-         } else if (Registers.RegisterType.REG_X_SBYTE.equals(register.getType())) {
-            String name = "xsby";
-            bindings.put(name, value);
-            return name;
-         } else if (Registers.RegisterType.REG_Y_SBYTE.equals(register.getType())) {
-            String name = "ysby";
-            bindings.put(name, value);
-            return name;
-         } else if (Registers.RegisterType.REG_A_SBYTE.equals(register.getType())) {
-            String name = "asby";
-            bindings.put(name, value);
-            return name;
          } else if (Registers.RegisterType.ZP_PTR_BYTE.equals(register.getType())) {
             String name = "zpptrby" + nextZpPtrIdx++;
             bindings.put(name, value);
@@ -287,7 +302,7 @@ public class AsmFragmentSignature {
          SymbolType constType;
          if (value instanceof ConstantVar) {
             constType = ((ConstantVar) value).getType();
-         } else if(value instanceof ConstantValue) {
+         } else if (value instanceof ConstantValue) {
             constType = SymbolTypeInference.inferType(program.getScope(), (ConstantValue) value);
          } else {
             throw new RuntimeException("Unhandled constant type " + value);
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java b/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
index 8188af597..bbaa05713 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
@@ -137,7 +137,7 @@ public class Pass4RegistersFinalize extends Pass2Base {
       if (SymbolType.isByte(varType)) {
          return new Registers.RegisterZpByte(currentZp++);
       } else if (SymbolType.isSByte(varType)) {
-         return new Registers.RegisterZpSignedByte(currentZp++);
+         return new Registers.RegisterZpByte(currentZp++);
       } else if (SymbolType.isWord(varType)) {
          Registers.RegisterZpWord registerZpWord =
                new Registers.RegisterZpWord(currentZp);
diff --git a/src/main/java/dk/camelot64/kickc/test/ref/casting.log b/src/main/java/dk/camelot64/kickc/test/ref/casting.log
index 3f8563f8c..af5ff5207 100644
--- a/src/main/java/dk/camelot64/kickc/test/ref/casting.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/casting.log
@@ -1483,8 +1483,8 @@ Complete equivalence classes
 Allocated zp ZP_BYTE:2 [ main::b#2 main::b#1 ]
 Allocated zp ZP_BYTE:3 [ w::i#2 w::i#1 ]
 Allocated zp ZP_BYTE:4 [ main::b2#0 ]
-Allocated zp ZP_SBYTE:5 [ main::$1 ]
-Allocated zp ZP_SBYTE:6 [ main::sb#0 ]
+Allocated zp ZP_BYTE:5 [ main::$1 ]
+Allocated zp ZP_BYTE:6 [ main::sb#0 ]
 Allocated zp ZP_BYTE:7 [ main::$3 ]
 Allocated zp ZP_BYTE:8 [ w::b2#0 ]
 INITIAL ASM
@@ -1641,17 +1641,17 @@ Statement [21] *((const byte*) SCREEN4#0 + (byte) w::i#2) ← (byte) w::b2#0 [ w
 Potential registers zp ZP_BYTE:2 [ main::b#2 main::b#1 ] : zp ZP_BYTE:2 , reg byte x , reg byte y , 
 Potential registers zp ZP_BYTE:3 [ w::i#2 w::i#1 ] : zp ZP_BYTE:3 , reg byte x , reg byte y , 
 Potential registers zp ZP_BYTE:4 [ main::b2#0 ] : zp ZP_BYTE:4 , reg byte a , reg byte x , reg byte y , 
-Potential registers zp ZP_SBYTE:5 [ main::$1 ] : zp ZP_SBYTE:5 , reg sbyte a , reg sbyte x , reg sbyte y , 
-Potential registers zp ZP_SBYTE:6 [ main::sb#0 ] : zp ZP_SBYTE:6 , reg sbyte a , reg sbyte x , reg sbyte y , 
+Potential registers zp ZP_BYTE:5 [ main::$1 ] : zp ZP_BYTE:5 , reg byte a , reg byte x , reg byte y , 
+Potential registers zp ZP_BYTE:6 [ main::sb#0 ] : zp ZP_BYTE:6 , reg byte a , reg byte x , reg byte y , 
 Potential registers zp ZP_BYTE:7 [ main::$3 ] : zp ZP_BYTE:7 , reg byte a , reg byte x , reg byte y , 
 Potential registers zp ZP_BYTE:8 [ w::b2#0 ] : zp ZP_BYTE:8 , reg byte x , reg byte y , 
 
 REGISTER UPLIFT SCOPES
-Uplift Scope [main] 25.93: zp ZP_BYTE:2 [ main::b#2 main::b#1 ] 22: zp ZP_BYTE:4 [ main::b2#0 ] 22: zp ZP_SBYTE:5 [ main::$1 ] 22: zp ZP_SBYTE:6 [ main::sb#0 ] 22: zp ZP_BYTE:7 [ main::$3 ] 
+Uplift Scope [main] 25.93: zp ZP_BYTE:2 [ main::b#2 main::b#1 ] 22: zp ZP_BYTE:4 [ main::b2#0 ] 22: zp ZP_BYTE:5 [ main::$1 ] 22: zp ZP_BYTE:6 [ main::sb#0 ] 22: zp ZP_BYTE:7 [ main::$3 ] 
 Uplift Scope [w] 30.25: zp ZP_BYTE:3 [ w::i#2 w::i#1 ] 11: zp ZP_BYTE:8 [ w::b2#0 ] 
 Uplift Scope [] 
 
-Uplifting [main] best 1056 combination reg byte x [ main::b#2 main::b#1 ] reg byte a [ main::b2#0 ] reg sbyte a [ main::$1 ] reg sbyte a [ main::sb#0 ] reg byte a [ main::$3 ] 
+Uplifting [main] best 1056 combination reg byte x [ main::b#2 main::b#1 ] reg byte a [ main::b2#0 ] reg byte a [ main::$1 ] reg byte a [ main::sb#0 ] reg byte a [ main::$3 ] 
 Uplifting [w] best 876 combination reg byte y [ w::i#2 w::i#1 ] reg byte x [ w::b2#0 ] 
 Uplifting [] best 876 combination 
 Removing instruction jmp b2
@@ -2085,7 +2085,7 @@ FINAL SYMBOL TABLE
 (byte*) SCREEN4
 (const byte*) SCREEN4#0 SCREEN4 = (const byte*) SCREEN#0+(byte/signed byte/word/signed word) 40*(byte/signed byte/word/signed word) 9
 (void()) main()
-(signed byte~) main::$1 reg sbyte a 22.0
+(signed byte~) main::$1 reg byte a 22.0
 (byte~) main::$3 reg byte a 22.0
 (label) main::@1
 (label) main::@2
@@ -2096,7 +2096,7 @@ FINAL SYMBOL TABLE
 (byte) main::b2
 (byte) main::b2#0 reg byte a 22.0
 (signed byte) main::sb
-(signed byte) main::sb#0 reg sbyte a 22.0
+(signed byte) main::sb#0 reg byte a 22.0
 (void()) w()
 (label) w::@1
 (label) w::@return
@@ -2115,8 +2115,8 @@ FINAL SYMBOL TABLE
 reg byte x [ main::b#2 main::b#1 ]
 reg byte y [ w::i#2 w::i#1 ]
 reg byte a [ main::b2#0 ]
-reg sbyte a [ main::$1 ]
-reg sbyte a [ main::sb#0 ]
+reg byte a [ main::$1 ]
+reg byte a [ main::sb#0 ]
 reg byte a [ main::$3 ]
 reg byte x [ w::b2#0 ]
 
diff --git a/src/main/java/dk/camelot64/kickc/test/ref/casting.sym b/src/main/java/dk/camelot64/kickc/test/ref/casting.sym
index 4844ec4c2..aa2806137 100644
--- a/src/main/java/dk/camelot64/kickc/test/ref/casting.sym
+++ b/src/main/java/dk/camelot64/kickc/test/ref/casting.sym
@@ -10,7 +10,7 @@
 (byte*) SCREEN4
 (const byte*) SCREEN4#0 SCREEN4 = (const byte*) SCREEN#0+(byte/signed byte/word/signed word) 40*(byte/signed byte/word/signed word) 9
 (void()) main()
-(signed byte~) main::$1 reg sbyte a 22.0
+(signed byte~) main::$1 reg byte a 22.0
 (byte~) main::$3 reg byte a 22.0
 (label) main::@1
 (label) main::@2
@@ -21,7 +21,7 @@
 (byte) main::b2
 (byte) main::b2#0 reg byte a 22.0
 (signed byte) main::sb
-(signed byte) main::sb#0 reg sbyte a 22.0
+(signed byte) main::sb#0 reg byte a 22.0
 (void()) w()
 (label) w::@1
 (label) w::@return
@@ -40,7 +40,7 @@
 reg byte x [ main::b#2 main::b#1 ]
 reg byte y [ w::i#2 w::i#1 ]
 reg byte a [ main::b2#0 ]
-reg sbyte a [ main::$1 ]
-reg sbyte a [ main::sb#0 ]
+reg byte a [ main::$1 ]
+reg byte a [ main::sb#0 ]
 reg byte a [ main::$3 ]
 reg byte x [ w::b2#0 ]
diff --git a/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.log b/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.log
index 3d8c89886..7f12f585f 100644
--- a/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.log
@@ -658,7 +658,7 @@ Complete equivalence classes
 [ main::i#2 main::i#1 ]
 [ main::j#2 main::j#1 ]
 [ main::$2 ]
-Allocated zp ZP_SBYTE:2 [ main::i#2 main::i#1 ]
+Allocated zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
 Allocated zp ZP_BYTE:3 [ main::j#2 main::j#1 ]
 Allocated zp ZP_BYTE:4 [ main::$2 ]
 INITIAL ASM
@@ -734,33 +734,37 @@ main: {
 }
 
 REGISTER UPLIFT POTENTIAL REGISTERS
-Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment xsby_lt_coby1_then_la1 allocation: reg sbyte x [ main::i#2 main::i#1 ] 
-Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment ysby_lt_coby1_then_la1 allocation: reg sbyte y [ main::i#2 main::i#1 ] 
+Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment xsby_lt_coby1_then_la1 allocation: reg byte x [ main::i#2 main::i#1 ] 
+Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment ysby_lt_coby1_then_la1 allocation: reg byte y [ main::i#2 main::i#1 ] 
 MISSING FRAGMENTS
   xsby_lt_coby1_then_la1
   ysby_lt_coby1_then_la1
 Statement [6] if((signed byte) main::i#2<(byte/signed byte/word/signed word) 127) goto main::@2 [ main::i#2 main::j#2 ] ( main:2 [ main::i#2 main::j#2 ] ) always clobbers reg byte a 
+Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
 Removing always clobbered register reg byte a as potential for zp ZP_BYTE:3 [ main::j#2 main::j#1 ]
-Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment xsby_lt_coby1_then_la1 allocation: reg sbyte x [ main::i#2 main::i#1 ] 
-Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment ysby_lt_coby1_then_la1 allocation: reg sbyte y [ main::i#2 main::i#1 ] 
+Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment xsby_lt_coby1_then_la1 allocation: reg byte x [ main::i#2 main::i#1 ] 
+Potential register analysis [6] if(main::i#2<127) goto main::@2 missing fragment ysby_lt_coby1_then_la1 allocation: reg byte y [ main::i#2 main::i#1 ] 
 MISSING FRAGMENTS
   xsby_lt_coby1_then_la1
   ysby_lt_coby1_then_la1
 Statement [6] if((signed byte) main::i#2<(byte/signed byte/word/signed word) 127) goto main::@2 [ main::i#2 main::j#2 ] ( main:2 [ main::i#2 main::j#2 ] ) always clobbers reg byte a 
-Potential registers zp ZP_SBYTE:2 [ main::i#2 main::i#1 ] : zp ZP_SBYTE:2 , reg sbyte a , reg sbyte x , reg sbyte y , 
+Potential registers zp ZP_BYTE:2 [ main::i#2 main::i#1 ] : zp ZP_BYTE:2 , reg byte x , reg byte y , 
 Potential registers zp ZP_BYTE:3 [ main::j#2 main::j#1 ] : zp ZP_BYTE:3 , reg byte x , reg byte y , 
 Potential registers zp ZP_BYTE:4 [ main::$2 ] : zp ZP_BYTE:4 , reg byte a , reg byte x , reg byte y , 
 
 REGISTER UPLIFT SCOPES
-Uplift Scope [main] 28.6: zp ZP_BYTE:3 [ main::j#2 main::j#1 ] 22: zp ZP_SBYTE:2 [ main::i#2 main::i#1 ] 22: zp ZP_BYTE:4 [ main::$2 ] 
+Uplift Scope [main] 28.6: zp ZP_BYTE:3 [ main::j#2 main::j#1 ] 22: zp ZP_BYTE:2 [ main::i#2 main::i#1 ] 22: zp ZP_BYTE:4 [ main::$2 ] 
 Uplift Scope [] 
 
-Uplifting [main] best 468 combination reg byte x [ main::j#2 main::j#1 ] zp ZP_SBYTE:2 [ main::i#2 main::i#1 ] reg byte a [ main::$2 ] 
+Uplifting [main] best 468 combination reg byte x [ main::j#2 main::j#1 ] zp ZP_BYTE:2 [ main::i#2 main::i#1 ] reg byte a [ main::$2 ] 
 Uplifting [] best 468 combination 
 MISSING FRAGMENTS
-  asby=_inc_asby
   xsby_lt_coby1_then_la1
   ysby_lt_coby1_then_la1
+Attempting to uplift remaining variables inzp ZP_BYTE:2 [ main::i#2 main::i#1 ]
+Uplifting [main] best 468 combination zp ZP_BYTE:2 [ main::i#2 main::i#1 ] 
+MISSING FRAGMENTS
+  ysby_lt_coby1_then_la1
 Removing instruction jmp b1
 Removing instruction jmp bend
 Removing instruction jmp b1
@@ -960,15 +964,15 @@ FINAL SYMBOL TABLE
 (label) main::@2
 (label) main::@return
 (signed byte) main::i
-(signed byte) main::i#1 i zp ZP_SBYTE:2 11.0
-(signed byte) main::i#2 i zp ZP_SBYTE:2 11.0
+(signed byte) main::i#1 i zp ZP_BYTE:2 11.0
+(signed byte) main::i#2 i zp ZP_BYTE:2 11.0
 (byte) main::j
 (byte) main::j#1 reg byte x 22.0
 (byte) main::j#2 reg byte x 6.6000000000000005
 (byte[]) main::screen
 (const byte[]) main::screen#0 screen = ((byte*))(word/signed word) 1024
 
-zp ZP_SBYTE:2 [ main::i#2 main::i#1 ]
+zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
 reg byte x [ main::j#2 main::j#1 ]
 reg byte a [ main::$2 ]
 
diff --git a/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.sym b/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.sym
index 6aa720444..47f5d2745 100644
--- a/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.sym
+++ b/src/main/java/dk/camelot64/kickc/test/ref/signed-bytes.sym
@@ -7,14 +7,14 @@
 (label) main::@2
 (label) main::@return
 (signed byte) main::i
-(signed byte) main::i#1 i zp ZP_SBYTE:2 11.0
-(signed byte) main::i#2 i zp ZP_SBYTE:2 11.0
+(signed byte) main::i#1 i zp ZP_BYTE:2 11.0
+(signed byte) main::i#2 i zp ZP_BYTE:2 11.0
 (byte) main::j
 (byte) main::j#1 reg byte x 22.0
 (byte) main::j#2 reg byte x 6.6000000000000005
 (byte[]) main::screen
 (const byte[]) main::screen#0 screen = ((byte*))(word/signed word) 1024
 
-zp ZP_SBYTE:2 [ main::i#2 main::i#1 ]
+zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
 reg byte x [ main::j#2 main::j#1 ]
 reg byte a [ main::$2 ]