diff --git a/.gitignore b/.gitignore
index b0fb5f2d0..3c771dfe2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,5 @@ integration-tests/src/compiled/*
 
 **/dist
 **/node_modules
+
+**/.antlr
diff --git a/fuzzing-tests/Aqua.g4 b/fuzzing-tests/Aqua.g4
new file mode 100644
index 000000000..d1f70c752
--- /dev/null
+++ b/fuzzing-tests/Aqua.g4
@@ -0,0 +1,100 @@
+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;
+
+basicType:
+	'⊥'
+	| '⊤'
+	| 'u8'
+	| 'u16'
+	| 'u32'
+	| 'u64'
+	| 'i8'
+	| 'i16'
+	| 'i32'
+	| 'i64'
+	| 'f32'
+	| 'f64'
+	| 'bool'
+	| 'string';
+
+namedType: ID;
+
+dataType:
+	basicType
+	| namedType
+	| ARRAY SP* dataType
+	| OPTION SP* dataType
+	| STREAM SP* dataType;
+
+arrowTypeAbilities_aux:
+	LBRACE SP* namedType SP* (COMMA SP* namedType)* SP* RBRACE;
+
+// Only data types are allowed as arguments for arrow type
+arrowTypeArgs_aux: (dataType SP* (COMMA SP* dataType)*)?;
+
+arrowTypeRet_aux:
+	typeParen_aux SP* (COMMA SP* typeParen_aux)*
+	| LPAREN RPAREN; // for no return
+
+arrowType:
+	arrowTypeAbilities_aux SP* arrowTypeArgs_aux SP* RARROW SP* arrowTypeRet_aux;
+
+type: dataType | arrowType;
+
+typeParen_aux: LPAREN SP* type SP* RPAREN | type;
+
+ARRAY: '[]';
+OPTION: '?';
+STREAM: '*';
+
+IF: 'if';
+FUNC: 'func';
+
+RARROW: '->';
+LPAREN: '(';
+RPAREN: ')';
+LBRACE: '{';
+RBRACE: '}';
+COLON: ':';
+COMMA: ',';
+SP: ' ';
+
+ID: [a-zA-Z][a-zA-Z_]+;
diff --git a/fuzzing-tests/README.md b/fuzzing-tests/README.md
new file mode 100644
index 000000000..2208b6078
--- /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 000000000..5979d3b17
--- /dev/null
+++ b/fuzzing-tests/requirements.txt
@@ -0,0 +1 @@
+grammarinator==19.3
\ No newline at end of file