diff --git a/src/compiler/fzl_parser.c b/src/compiler/fzl_parser.c
index 6bf159d..559bf55 100644
--- a/src/compiler/fzl_parser.c
+++ b/src/compiler/fzl_parser.c
@@ -1,5 +1,5 @@
-#include "compiler/fzl_token.h"
 #include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -166,22 +166,29 @@ fzl_node_t *parse_primary(fzl_parser_t *parser)
 
     while (peek(parser) && peek(parser)->type != FZL_TOKTYPE_STR_FORMAT_END)
     {
-      if (remainder <= count)
-      {
-        remainder *= 2;
-        entries = realloc(entries, remainder * sizeof(fzl_node_t *));
-        if (!entries)
-        {
-          snprintf(plast_err, sizeof(plast_err), "out of memory");
-          return NULL;
-        }
-      }
-
       if (is(parser, FZL_TOKTYPE_STR_FORMAT_END))
         break;
 
+      if (remainder <= count)
+      {
+        remainder *= 2;
+        fzl_node_t **newentries =
+            realloc(entries, remainder * sizeof(fzl_node_t *));
+        if (!newentries)
+        {
+          snprintf(plast_err, sizeof(plast_err), "out of memory");
+          for (size_t i = 0; i < count; i++)
+            fzl_freeast(entries[i]);
+
+          free(entries);
+          return NULL;
+        }
+
+        entries = newentries;
+      }
+
       fzl_node_t *expr = parse_expression(parser);
-      if (!expr)
+      if (expr == NULL)
       {
         for (size_t i = 0; i < count; i++)
           fzl_freeast(entries[i]);
@@ -192,6 +199,7 @@ fzl_node_t *parse_primary(fzl_parser_t *parser)
 
       entries[count++] = expr;
     }
+
     fzl_token_t *end = consume(parser);
     if (end->type != FZL_TOKTYPE_STR_FORMAT_END)
     {
@@ -644,8 +652,8 @@ fzl_node_t *parse_new(fzl_parser_t *parser)
 
   fzl_token_t *new    = consume(parser);
   fzl_node_t *objname = parse_or(parser);
-  if (objname->type != FZL_NODETYPE_IDENTIFIER &&
-      objname->type != FZL_NODETYPE_FIELD)
+  if (!objname || (objname->type != FZL_NODETYPE_IDENTIFIER &&
+                   objname->type != FZL_NODETYPE_FIELD))
   {
     fzl_freeast(objname);
     snprintf(plast_err, sizeof(plast_err),
@@ -1332,7 +1340,10 @@ fzl_node_t *parse_program(fzl_parser_t *parser)
   {
     node = parse_statement(parser);
     if (!node)
+    {
+      fzl_freeast(first);
       return NULL;
+    }
 
     if (!last)
     {
@@ -1398,50 +1409,35 @@ void fzl_freeast(fzl_node_t *root)
         if (root->list.entries)
         {
           for (size_t i = 0; i < root->list.entry_count; i++)
-            if (root->list.entries[i])
-              fzl_freeast(root->list.entries[i]);
+            fzl_freeast(root->list.entries[i]);
 
           free(root->list.entries);
         }
         break;
 
       case FZL_NODETYPE_CALL:
-        if (root->call.callee)
-          fzl_freeast(root->call.callee);
+        fzl_freeast(root->call.callee);
 
         if (root->call.args_count)
         {
           for (size_t i = 0; i < root->call.args_count; i++)
-            if (root->call.args[i])
-              fzl_freeast(root->call.args[i]);
+            fzl_freeast(root->call.args[i]);
         }
         if (root->call.args)
           free(root->call.args);
         break;
 
       case FZL_NODETYPE_CONDITIONAL:
-        if (root->cond.condition)
-          fzl_freeast(root->cond.condition);
-
-        if (root->cond.true_block)
-          fzl_freeast(root->cond.true_block);
-
-        if (root->cond.else_block)
-          fzl_freeast(root->cond.else_block);
+        fzl_freeast(root->cond.condition);
+        fzl_freeast(root->cond.true_block);
+        fzl_freeast(root->cond.else_block);
         break;
 
       case FZL_NODETYPE_LOOP:
-        if (root->loop.init)
-          fzl_freeast(root->loop.init);
-
-        if (root->loop.cond)
-          fzl_freeast(root->loop.cond);
-
-        if (root->loop.step)
-          fzl_freeast(root->loop.step);
-
-        if (root->loop.body)
-          fzl_freeast(root->loop.body);
+        fzl_freeast(root->loop.init);
+        fzl_freeast(root->loop.cond);
+        fzl_freeast(root->loop.step);
+        fzl_freeast(root->loop.body);
         break;
 
       case FZL_NODETYPE_ADD:
@@ -1459,17 +1455,14 @@ void fzl_freeast(fzl_node_t *root)
       case FZL_NODETYPE_GREATER:
       case FZL_NODETYPE_GREATER_EQUAL:
       case FZL_NODETYPE_ASSIGN:
-        if (root->binary_op.left)
-          fzl_freeast(root->binary_op.left);
-        if (root->binary_op.right)
-          fzl_freeast(root->binary_op.right);
+        fzl_freeast(root->binary_op.left);
+        fzl_freeast(root->binary_op.right);
         break;
 
       case FZL_NODETYPE_UNARY_PLUS:
       case FZL_NODETYPE_UNARY_MINUS:
       case FZL_NODETYPE_NOT:
-        if (root->unary_op.operand)
-          fzl_freeast(root->unary_op.operand);
+        fzl_freeast(root->unary_op.operand);
         break;
 
       case FZL_NODETYPE_FUNCTION:
@@ -1481,8 +1474,7 @@ void fzl_freeast(fzl_node_t *root)
         break;
 
       case FZL_NODETYPE_RETURN:
-        if (root->ret.value)
-          fzl_freeast(root->ret.value);
+        fzl_freeast(root->ret.value);
         break;
 
       case FZL_NODETYPE_CLASS:
@@ -1507,8 +1499,7 @@ void fzl_freeast(fzl_node_t *root)
         break;
 
       case FZL_NODETYPE_DECLARATION:
-        if (root->var.identifier)
-          fzl_freeast(root->var.identifier);
+        fzl_freeast(root->var.identifier);
         break;
     }
 
diff --git a/tests/programs/neg_fmtstr_with_unknown_inside.fzs b/tests/programs/neg_fmtstr_with_unknown_inside.fzs
new file mode 100644
index 0000000..95839a5
--- /dev/null
+++ b/tests/programs/neg_fmtstr_with_unknown_inside.fzs
@@ -0,0 +1,2 @@
+printline($"Something's on the {way}")
+
diff --git a/tests/programs/neg_unterminatd_fmtstr.fzs b/tests/programs/neg_unterminatd_fmtstr.fzs
new file mode 100644
index 0000000..5181e3b
--- /dev/null
+++ b/tests/programs/neg_unterminatd_fmtstr.fzs
@@ -0,0 +1 @@
+$"jopa {abc}
diff --git a/tests/programs/pos_fmtstr.fzs b/tests/programs/pos_fmtstr.fzs
new file mode 100644
index 0000000..daa4931
--- /dev/null
+++ b/tests/programs/pos_fmtstr.fzs
@@ -0,0 +1,6 @@
+int a1 = 2 * 2;
+printline($"First tests: build string and print. 2 * 2 = {a1}");
+
+str a2 = "Mike Tyson";
+printline($"Hello, {a2}");
+