diff --git a/include/lexer.h b/include/lexer.h
index eccf1dc..4f3c211 100644
--- a/include/lexer.h
+++ b/include/lexer.h
@@ -3,10 +3,11 @@
 
 #include <stddef.h>
 #include <stdbool.h>
+#include <stdint.h>
 
 // For identifing
 typedef enum {
-    NODE_NUMBER,
+    NODE_INTEGER,
     NODE_BINARY_OP,
 } ASTNodeType;
 
@@ -41,7 +42,7 @@ typedef enum {
 typedef struct ASTNode {
     ASTNodeType type;
     union {
-        double number;
+        int64_t integer;
         struct {
             struct ASTNode *left;
             struct ASTNode *right;
@@ -69,7 +70,7 @@ size_t ASTNodeArray_len(ASTNodeArray *arr);
 // Lexer funtions as well as few functionality
 LexerErr tokenize(const char* input, ASTNodeArray *out);
 LexerErr tokenize_number(const char* input, size_t *offset, ASTNode *out);
-LexerErr string_to_number(const char* input, size_t *offset, double *number);
+LexerErr string_to_number(const char* input, size_t *offset, int64_t *number);
 void reverser_string(char* input);
 
 #endif // !LEXER_H
diff --git a/src/lexer.c b/src/lexer.c
index b0abbb8..4663f3f 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -114,7 +114,7 @@ size_t ASTNodeArray_len(ASTNodeArray *arr) {
 
 // CURRENTLY, it only supports ints, not clear how floating
 // point is implemented but i'll figure it out
-LexerErr string_to_number(const char *input, size_t *offset, double *number) {
+LexerErr string_to_number(const char *input, size_t *offset, int64_t *number) {
     char buf[128] = { '\0' };
     size_t buf_pos = 0;
 
@@ -130,7 +130,7 @@ LexerErr string_to_number(const char *input, size_t *offset, double *number) {
     }
     
     int c = 0;
-    long count = 0;
+    int64_t count = 0;
     while (buf[c] != '\0') {
         
         int digit = buf[c] - '0';
@@ -144,7 +144,7 @@ LexerErr string_to_number(const char *input, size_t *offset, double *number) {
         c++;
     }
 
-    *number = (double) count;
+    *number = count;
     *offset = current;
     return LEXER_OK;
 }
diff --git a/test/test_ASTNodeArray.c b/test/test_ASTNodeArray.c
index cc28297..59c98cb 100644
--- a/test/test_ASTNodeArray.c
+++ b/test/test_ASTNodeArray.c
@@ -12,18 +12,18 @@ static void test_array_push(void **state) {
     // We use 2 to force resize and checking anything wrong with malloc
     ASTNodeArray arr = ASTNodeArray_init(2);
     ASTNode node1 = {
-        .type = NODE_NUMBER,
-        .data = { .number = 90 }
+        .type = NODE_INTEGER,
+        .data = { .integer = 90 }
     };
 
     ASTNode node2 = {
-        .type = NODE_NUMBER,
-        .data = { .number = 80 }
+        .type = NODE_INTEGER,
+        .data = { .integer = 80 }
     };
 
     ASTNode node3 = {
-        .type = NODE_NUMBER,
-        .data = { .number = 70 }
+        .type = NODE_INTEGER,
+        .data = { .integer = 70 }
     };
 
     assert_int_equal(ASTNodeArray_push(&arr, node1), ARRAY_OK);
@@ -44,18 +44,18 @@ static void test_array_pop(void **state) {
     // Set to force desize
     ASTNodeArray arr = ASTNodeArray_init(16);
     ASTNode node1 = {
-        .type = NODE_NUMBER,
-        .data = { .number = 90 }
+        .type = NODE_INTEGER,
+        .data = { .integer = 90 }
     };
 
     ASTNode node2 = {
-        .type = NODE_NUMBER,
-        .data = { .number = 80 }
+        .type = NODE_INTEGER,
+        .data = { .integer = 80 }
     };
 
     ASTNode node3 = {
-        .type = NODE_NUMBER,
-        .data = { .number = 70 }
+        .type = NODE_INTEGER,
+        .data = { .integer = 70 }
     };
 
     assert_int_equal(ASTNodeArray_push(&arr, node1), ARRAY_OK);
@@ -69,8 +69,8 @@ static void test_array_pop(void **state) {
 
     ASTNode node4;
     assert_int_equal(ASTNodeArray_pop(&arr, 1, &node4), ARRAY_OK);
-    assert_int_equal(node4.type, NODE_NUMBER);
-    assert_int_equal(node4.data.number, 80);
+    assert_int_equal(node4.type, NODE_INTEGER);
+    assert_int_equal(node4.data.integer, 80);
 
     ASTNodeArray_free(&arr);
 }
diff --git a/test/test_lexer.c b/test/test_lexer.c
index 8d59e72..e9d1c81 100644
--- a/test/test_lexer.c
+++ b/test/test_lexer.c
@@ -11,7 +11,7 @@ static void test_string_to_number(void **state) {
 
     char num[16] = "2333t55";
     size_t offset = 0;
-    double result = 0;
+    int64_t result = 0;
     assert_int_equal(string_to_number(num, &offset, &result), 0);
 
     assert_int_equal(offset, 4);