diff --git a/src/chunk.c b/src/chunk.c
index e36ddd4..77e73f8 100644
--- a/src/chunk.c
+++ b/src/chunk.c
@@ -6,6 +6,7 @@ void newChunk(Chunk* chunk) {
   chunk->count = 0;
   chunk->capacity = 0;
   chunk->code = NULL;
+  newValueArray(&chunk->constants);
 }
 
 void writeChunk(Chunk *chunk, uint8_t byte) {
@@ -18,5 +19,16 @@ void writeChunk(Chunk *chunk, uint8_t byte) {
 
   chunk->code[chunk->count] = byte;
   chunk->count++;
-
 }
+
+void freeChunk(Chunk *chunk) {
+  FREE_ARRAY(uint8_t, chunk->code, chunk->capacity);
+  freeValueArray(&chunk->constants);
+  newChunk(chunk);
+}
+
+int addConstant(Chunk* chunk, Value value) {
+  writeValueArray(&chunk->constants, value);
+  return chunk->constants.count - 1;
+}
+
diff --git a/src/chunk.h b/src/chunk.h
index 6f75384..9df161f 100644
--- a/src/chunk.h
+++ b/src/chunk.h
@@ -3,8 +3,11 @@
 
 #include "common.h"
 #include "memory.h"
+#include "value.h"
 
 typedef enum {
+  OP_NOOP,
+  OP_CONSTANT,
   OP_RETURN, 
 } OpCode;
 
@@ -12,10 +15,12 @@ typedef struct Chunk {
   int count;
   int capacity;
   uint8_t *code;
+  ValueArray constants;
 } Chunk;
 
 void newChunk(Chunk *chunk);
 void freeChunk(Chunk *chunk);
 void writeChunk(Chunk *chunk, uint8_t byte);
+int addConstant(Chunk *chunk, Value value);
 
 #endif
diff --git a/src/debug.c b/src/debug.c
index 4eb7eba..12f63c4 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 
 #include "debug.h"
+#include "value.h"
 
 void disassembleChunk(Chunk* chunk, const char* name) {
   printf("== %s ==\n", name);
@@ -10,6 +11,15 @@ void disassembleChunk(Chunk* chunk, const char* name) {
   }
 }
 
+static int constantInstruction(const char* name, Chunk* chunk,
+                               int offset) {
+  uint8_t constant = chunk->code[offset + 1];
+  printf("%-16s %4d '", name, constant);
+  printValue(chunk->constants.values[constant]);
+  printf("'\n");
+  return offset + 2;
+}
+
 static int simpleInstruction(const char* name, int offset) {
   printf("%s\n", name);
   return offset + 1;
@@ -20,6 +30,10 @@ int disassembleInstruction(Chunk* chunk, int offset) {
 
   uint8_t instruction = chunk->code[offset];
   switch (instruction) {
+    case OP_NOOP:
+      return simpleInstruction("OP_NOOP", offset);
+    case OP_CONSTANT:
+      return constantInstruction("OP_CONSTANT", chunk, offset);
     case OP_RETURN:
       return simpleInstruction("OP_RETURN", offset);
     default:
diff --git a/src/main.c b/src/main.c
index 245eb31..4edaa0a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,6 +5,11 @@
 int main(int argc, const char** argv) {
   Chunk chunk;
   newChunk(&chunk);
+
+  int constant = addConstant(&chunk, 1.2);
+  writeChunk(&chunk, OP_CONSTANT);
+  writeChunk(&chunk, constant);
+
   writeChunk(&chunk, OP_RETURN);
 
   disassembleChunk(&chunk, "test chunk");
diff --git a/src/memory.c b/src/memory.c
index c93a6b3..3a928d4 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -14,8 +14,3 @@ void* reallocate(void *pointer, size_t oldSize, size_t newSize) {
   return result;
 }
 
-void freeChunk(Chunk *chunk) {
-  FREE_ARRAY(uint8_t, chunk->code, chunk->capacity);
-  newChunk(chunk);
-}
-
diff --git a/src/value.c b/src/value.c
new file mode 100644
index 0000000..664afdb
--- /dev/null
+++ b/src/value.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+#include "memory.h"
+#include "value.h"
+
+void newValueArray(ValueArray *array) {
+  array->values = NULL;
+  array->capacity = 0;
+  array->count = 0;
+}
+
+void writeValueArray(ValueArray *array, Value value) {
+  if (array->capacity < array->count + 1) {
+    int oldCapacity = array->capacity;
+    array->capacity = GROW_CAPACITY(oldCapacity);
+    array->values = GROW_ARRAY(Value, array->values,
+                               oldCapacity, array->capacity);
+  }
+
+  array->values[array->count] = value;
+  array->count++;
+}
+
+void freeValueArray(ValueArray *array) {
+  FREE_ARRAY(Value, array->values, array->capacity);
+  newValueArray(array);
+}
+
+void printValue(Value value) {
+  printf("%g", value);
+}
diff --git a/src/value.h b/src/value.h
new file mode 100644
index 0000000..6a8c1bd
--- /dev/null
+++ b/src/value.h
@@ -0,0 +1,19 @@
+#ifndef ztl_value_h
+#define ztl_value_h
+
+#include "common.h"
+
+typedef double Value;
+
+typedef struct {
+  int capacity;
+  int count;
+  Value *values;
+} ValueArray;
+
+void newValueArray(ValueArray *array);
+void writeValueArray(ValueArray *array, Value value);
+void freeValueArray(ValueArray *array);
+void printValue(Value value);
+
+#endif