diff --git a/include/ground.h b/include/ground.h
index abbdd6d..24a1166 100644
--- a/include/ground.h
+++ b/include/ground.h
@@ -529,7 +529,7 @@ struct _Ground {
             struct GroundExecutionResult (*execute) (GroundBytecodeInstruction* instruction, GroundBytecodeHeap* heap);
         } Instruction;
         struct {
-            void         (*set) (GroundBytecodeHeap* heap, GroundSize idx, GroundValue value);
+            void         (*set) (GroundBytecodeHeap* heap, GroundSize idx, GroundBytecodeValue value);
             GroundValue* (*get) (GroundBytecodeHeap* heap, GroundSize idx);
         } Heap;
     } Bytecode;
diff --git a/src/Bytecode/Instruction/execute.c b/src/Bytecode/Instruction/execute.c
index 9c643be..f7c0113 100644
--- a/src/Bytecode/Instruction/execute.c
+++ b/src/Bytecode/Instruction/execute.c
@@ -82,18 +82,24 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
     PRINT: {
         for (GroundSize i = 0; i < instruction->args.len; i++) {
             printValue(HEAP_GET(heap, instruction->args.at[i]));
+            printf(" ");
         }
         return CONTINUE;
     }
     PRINTLN: {
         for (GroundSize i = 0; i < instruction->args.len; i++) {
             printValue(HEAP_GET(heap, instruction->args.at[i]));
+            printf(" ");
         }
         printf("\n");
         return CONTINUE;
     }
     SET: {
-        HEAP_SET(heap, instruction->args.at[0], *HEAP_GET(heap, instruction->args.at[1]));
+        if (instruction->args.at[0] != instruction->args.at[1]) {
+            GroundBytecodeValue copy = Ground.Copy.BytecodeValue(HEAP_GET(heap, instruction->args.at[1]));
+            Ground.Free.BytecodeValue(&heap->heap[instruction->args.at[0]]);
+            HEAP_SET(heap, instruction->args.at[0], copy);
+        }
         return CONTINUE;
     }
     GETTYPE: {
@@ -179,6 +185,7 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
                         }
                         sprintf(buf, "%s%s", left->as.String.cstr, right->as.String.cstr);
                         *final = Ground.New.BytecodeValue(Ground.New.Value.String(Ground.New.String(buf)));
+                        free(buf);
                         break;
                     }
                     default: {
@@ -666,7 +673,6 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
         return CONTINUE;
     }
     TOSTRING: {
-        GroundBytecodeValue* final = HEAP_GET(heap, instruction->args.at[1]);
         GroundBytecodeValue* in = HEAP_GET(heap, instruction->args.at[0]);
 
         char buf[4096];
@@ -689,7 +695,6 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
                 break;
             }
             case GroundType_String: {
-                *in = Ground.New.BytecodeValue(Ground.New.Value.String(final->as.String));
                 return CONTINUE;
             }
 
@@ -785,8 +790,8 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
         // Now we run the thingy
         GroundBytecodeValue result = Ground.Bytecode.Program.execute(function->program.ground, &newHeap);
 
-        // And store the result 
-        HEAP_SET(heap, instruction->args.at[instruction->args.len - 1], result);
+        // Deep copy the result before freeing the function's heap
+        GroundBytecodeValue resultCopy = Ground.Copy.BytecodeValue(&result);
 
         // Clean up the new heap 
         for (GroundSize i = 0; i < newHeap.len; i++) {
@@ -794,6 +799,9 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
         }
         free(newHeap.heap);
 
+        // And store the result 
+        HEAP_SET(heap, instruction->args.at[instruction->args.len - 1], resultCopy);
+
         return CONTINUE;
     }
     CALLMETHOD: {
diff --git a/src/Free/String.c b/src/Free/String.c
index c537028..1094fb1 100644
--- a/src/Free/String.c
+++ b/src/Free/String.c
@@ -4,5 +4,6 @@
 
 void _GroundFreeString(GroundString* in) {
     free(in->cstr);
+    in->cstr = NULL;
     in->len = 0;
 }
diff --git a/src/New/Bytecode.c b/src/New/Bytecode.c
index 470e9f3..09e4660 100644
--- a/src/New/Bytecode.c
+++ b/src/New/Bytecode.c
@@ -238,7 +238,7 @@ GroundBytecode _GroundNewBytecode(GroundProgram* program, GroundState* state) {
     if (Ground.Flags.error) return bytecode;
 
     // Allocate heap
-    bytecode.heap.heap = malloc(sizeof(GroundValue) * size);
+    bytecode.heap.heap = malloc(sizeof(GroundBytecodeValue) * size);
     if (bytecode.heap.heap == NULL) {
         Ground.Log.Error("malloc failed in Ground.New.Bytecode");
         Ground.Flags.error = true;
diff --git a/src/libmain.c b/src/libmain.c
index f13241d..507045c 100644
--- a/src/libmain.c
+++ b/src/libmain.c
@@ -109,7 +109,7 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
 void _GroundBytecodeSave(GroundBytecode* bytecode, const char* path);
 GroundBytecode _GroundBytecodeLoad(const char* path);
 
-void _GroundBytecodeHeapSet(GroundBytecodeHeap* heap, GroundSize idx, GroundValue value);
+void _GroundBytecodeHeapSet(GroundBytecodeHeap* heap, GroundSize idx, GroundBytecodeValue value);
 GroundValue* _GroundBytecodeHeapGet(GroundBytecodeHeap* heap, GroundSize idx);