diff --git a/parser.zig b/parser.zig
index 42a4ac7..7edd7ea 100644
--- a/parser.zig
+++ b/parser.zig
@@ -131,13 +131,41 @@ fn checkIfBlockStillMatches(line: *[]const u8, block: Block) bool {
         },
     };
 }
-fn getHeadingLevel(line: []const u8) u8 {
-    var level: u8 = 0;
-    for (line) |char| {
-        if (level == 6) break;
-        if (char == '#') level += 1 else break;
+
+const ATXHeading = struct {
+    spaces: u2,
+    level: u3,
+    pub fn content(self: ATXHeading, line: []const u8) []const u8 {
+        if (line.len > self.spaces + self.level) {
+            return line[self.spaces + self.level + 1 ..];
+        } else {
+            // If it's an empty heading without a space (example 79)
+            return line[self.spaces + self.level ..];
+        }
     }
-    return level;
+};
+
+fn parseATXHeading(line: []const u8) ?ATXHeading {
+    var spaces: u2 = 0;
+    for (line) |char| {
+        if (char == ' ' and spaces != 3)
+            spaces += 1
+        else if (char == '#')
+            break
+        else
+            return null;
+    }
+    var level: u3 = 0;
+    for (line[spaces..]) |char| {
+        if (char == '#' and level != 6)
+            level += 1
+        else if (char == ' ' or char == '\t' or char == '\n')
+            break
+        else
+            return null;
+    }
+    if (level == 0) return null;
+    return ATXHeading{ .level = level, .spaces = spaces };
 }
 fn checkIfBlockStarts(allocator: std.mem.Allocator, line: *[]const u8) !?Block {
     if (std.mem.startsWith(u8, line.*, ">")) {
@@ -152,15 +180,11 @@ fn checkIfBlockStarts(allocator: std.mem.Allocator, line: *[]const u8) !?Block {
             .kind = .{ .bullet = '*' },
             .tight = false,
         } };
-    } else if (std.mem.startsWith(u8, line.*, "#")) {
-        const level = getHeadingLevel(line.*);
-        if (line.*[level..].len != 0) {
-            if (line.*[level] != ' ' and line.*[level] != '\t') return null;
-            line.* = line.*[level + 1 ..];
-        }
+    } else if (parseATXHeading(line.*)) |heading| {
+        line.* = heading.content(line.*);
         return Block{ .heading = .{
             .text = try allocator.alloc(u8, 0),
-            .level = level,
+            .level = heading.level,
         } };
     }
     return null;
diff --git a/readme.md b/readme.md
index 9368c91..97861e0 100644
--- a/readme.md
+++ b/readme.md
@@ -19,7 +19,7 @@ Ver [cli.zig](cli.zig)
 
 ## CommonMark
 
-Actualmente: `122 passed, 530 failed, 0 errored, 0 skipped`
+Actualmente: `123 passed, 529 failed, 0 errored, 0 skipped`
 
 Para correr los tests: