diff --git a/tests/irdl/test_declarative_assembly_format.py b/tests/irdl/test_declarative_assembly_format.py
index 99cd7e5173..c1f144a4af 100644
--- a/tests/irdl/test_declarative_assembly_format.py
+++ b/tests/irdl/test_declarative_assembly_format.py
@@ -1601,6 +1601,35 @@ class FunctionalTypeOp(IRDLOperation):
     ctx.load_op(FunctionalTypeOp)
 
 
+@pytest.mark.parametrize(
+    "program",
+    [
+        "%0 = test.functional_type %1, %2 : (i32, i32) -> i32",
+        "%0, %1 = test.functional_type %2, %3 : (i32, i32) -> (i32, i32)",
+        "%0 = test.functional_type %1 : (i32) -> i32",
+    ],
+)
+def test_functional_type_with_operands_and_results(program: str):
+    """
+    Test the parsing of the functional-type directive using the operands and
+    results directives
+    """
+
+    @irdl_op_definition
+    class FunctionalTypeOp(IRDLOperation):
+        name = "test.functional_type"
+
+        op1 = operand_def()
+        ops2 = var_operand_def()
+        res1 = var_result_def()
+        res2 = result_def()
+
+        assembly_format = "operands attr-dict `:` functional-type(operands, results)"
+
+    ctx = MLContext()
+    ctx.load_op(FunctionalTypeOp)
+
+
 ################################################################################
 # Regions                                                                     #
 ################################################################################
diff --git a/xdsl/irdl/declarative_assembly_format.py b/xdsl/irdl/declarative_assembly_format.py
index 9bd6d3acb3..727ffe4b2b 100644
--- a/xdsl/irdl/declarative_assembly_format.py
+++ b/xdsl/irdl/declarative_assembly_format.py
@@ -660,9 +660,11 @@ def parse_optional(self, parser: Parser, state: ParsingState) -> bool:
         return bool(operands)
 
     def parse_single_type(self, parser: Parser, state: ParsingState) -> None:
-        if len(state.operand_types) > 1:
-            parser.raise_error("Expected multiple types but received one.")
-        state.operand_types[0] = parser.parse_type()
+        pos_start = parser.pos
+        if s := self._set_using_variadic_index(
+            state.operand_types, "operand types", (parser.parse_type(),)
+        ):
+            parser.raise_error(s, at_position=pos_start, end_position=parser.pos)
 
     def parse_many_types(self, parser: Parser, state: ParsingState) -> bool:
         pos_start = parser.pos
@@ -782,9 +784,11 @@ class ResultsDirective(OperandsOrResultDirective):
     """
 
     def parse_single_type(self, parser: Parser, state: ParsingState) -> None:
-        if len(state.result_types) > 1:
-            parser.raise_error("Expected multiple types but received one.")
-        state.result_types[0] = parser.parse_type()
+        pos_start = parser.pos
+        if s := self._set_using_variadic_index(
+            state.result_types, "result types", (parser.parse_type(),)
+        ):
+            parser.raise_error(s, at_position=pos_start, end_position=parser.pos)
 
     def parse_many_types(self, parser: Parser, state: ParsingState) -> bool:
         pos_start = parser.pos