diff --git a/.gitignore b/.gitignore
index b01daccb..a558afce 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,3 +11,5 @@ project/target
 
 npm/aqua.js
 **/node_modules
+
+**/.antlr
diff --git a/fuzzing-tests/Aqua.g4 b/fuzzing-tests/Aqua.g4
new file mode 100644
index 00000000..7af55031
--- /dev/null
+++ b/fuzzing-tests/Aqua.g4
@@ -0,0 +1,51 @@
+grammar Aqua;
+
+tokens {
+	INDENT,
+	DEDENT,
+	NL
+}
+
+@lexer::members {
+# A hack to support indentation
+def create_node(self, node, *args, **kwargs):
+    result = super().create_node(node, *args, **kwargs)
+
+    if not hasattr(self, "indent_level"):
+        self.indent_level = 0
+
+    if node.name == "INDENT": 
+        self.indent_level += 1
+        result.src = "\n" + "  " * self.indent_level
+    elif node.name == "DEDENT":
+        self.indent_level -= 1
+        result.src = "\n" + "  " * self.indent_level
+    elif node.name == "NL":
+        result.src = "\n" + "  " * self.indent_level
+    
+    return result
+}
+
+prog: function+;
+
+function: FUNC SP+ closure;
+
+closure:
+	ID LPAREN ((typedId COMMA SP*)* typedId)? RPAREN COLON block;
+
+block: INDENT ('expr' NL | ifStat)+ DEDENT;
+
+ifStat: IF SP+ ID COLON block;
+
+typedId: ID SP* COLON SP* type;
+
+type: 'u16';
+
+LPAREN: '(';
+RPAREN: ')';
+COLON: ':';
+COMMA: ',';
+SP: ' ';
+IF: 'if';
+FUNC: 'func';
+ID: [a-zA-Z][a-zA-Z_]+;
diff --git a/fuzzing-tests/README.md b/fuzzing-tests/README.md
new file mode 100644
index 00000000..2208b607
--- /dev/null
+++ b/fuzzing-tests/README.md
@@ -0,0 +1,21 @@
+# Fuzzing tests for Aqua Compiler
+
+## Installation
+
+```sh
+python3 -m pip install -r requirements.txt
+```
+
+## Usage
+
+File `Aqua.g4` contains ANTLRv4 grammar of Aqua Language.
+
+The following command will generate python fuzzing input generators for Aqua in `generated` dir:
+```sh
+grammarinator-process Aqua.g4 -o generated
+```
+
+The following command will generate `N` tests in `tests` dir with maximum grammar depth `D`:
+```sh
+grammarinator-generate -p generated/AquaUnparser.py -l generated/AquaUnlexer -r prog -n N -d D
+```
\ No newline at end of file
diff --git a/fuzzing-tests/requirements.txt b/fuzzing-tests/requirements.txt
new file mode 100644
index 00000000..5979d3b1
--- /dev/null
+++ b/fuzzing-tests/requirements.txt
@@ -0,0 +1 @@
+grammarinator==19.3
\ No newline at end of file