diff --git a/Cargo.toml b/Cargo.toml
index 56d4352..dddee04 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,7 +7,7 @@ keywords = ["parse", "dump", "serialize", "deserialize", "stringify"]
 license = "MIT"
 name = "gura"
 repository = "https://github.com/gura-conf/gura-rs-parser"
-version = "0.5.1"
+version = "0.5.2"
 
 [dependencies]
 float-pretty-print = "0.1.0"
diff --git a/src/parser.rs b/src/parser.rs
index bf20ef5..b1115a6 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1310,7 +1310,7 @@ fn number(text: &mut Input) -> RuleResult {
 
     // Checks hexadecimal, octal and binary format
     let prefix = result.get(0..2).unwrap_or("");
-    if vec!["0x", "0o", "0b"].contains(&prefix) {
+    if ["0x", "0o", "0b"].contains(&prefix) {
         let without_prefix = result[2..].to_string();
         let base = match prefix {
             "0x" => 16,
@@ -1489,6 +1489,7 @@ fn pair(text: &mut Input) -> RuleResult {
     if let GuraType::Indentation(current_indentation_level) =
         matches(text, vec![Box::new(ws_with_indentation)])?
     {
+        println!("current_indentation_level: {}", current_indentation_level);
         let matched_key = matches(text, vec![Box::new(key)])?;
 
         if let GuraType::String(key_value) = matched_key {
@@ -1496,6 +1497,7 @@ fn pair(text: &mut Input) -> RuleResult {
 
             // Check indentation
             let last_indentation_block = get_last_indentation_level(text);
+            println!("last_indentation_block: {:?}", last_indentation_block);
 
             // Check if indentation is divisible by 4
             if current_indentation_level % 4 != 0 {
@@ -1524,6 +1526,16 @@ fn pair(text: &mut Input) -> RuleResult {
                     Ordering::Equal => (),
                 }
             } else {
+                // If it's the first pair, the indentation level is should be 0
+                if current_indentation_level > 0 {
+                    return Err(GuraError {
+                        pos: pos_before_pair,
+                        line: text.line,
+                        msg: String::from("First pair must have indentation level 0"),
+                        kind: Error::InvalidIndentationError,
+                    });
+                }
+
                 text.indentation_levels.push(current_indentation_level);
             }
 
diff --git a/tests/exception_report.rs b/tests/exception_report.rs
index 4f43d97..b9f7a44 100644
--- a/tests/exception_report.rs
+++ b/tests/exception_report.rs
@@ -226,3 +226,9 @@ fn test_duplicated_import_1() {
 fn test_duplicated_import_2() {
     test_fail("importing_error_2.ura", Error::DuplicatedImportError, 86, 5);
 }
+
+/// Tests issue https://github.com/gura-conf/gura/issues/12
+#[test]
+fn test_array_issue_12() {
+    test_fail("issue_12.ura", Error::InvalidIndentationError, 0, 2);
+}
diff --git a/tests/exception_report/tests-files/issue_12.ura b/tests/exception_report/tests-files/issue_12.ura
new file mode 100644
index 0000000..145c37e
--- /dev/null
+++ b/tests/exception_report/tests-files/issue_12.ura
@@ -0,0 +1,6 @@
+
+            hosts: [
+                "alpha",
+                "omega"
+            ]
+            
\ No newline at end of file