diff --git a/cmem_plugin_base/dataintegration/parameter/graph.py b/cmem_plugin_base/dataintegration/parameter/graph.py
index 8dd6575..b849c8a 100644
--- a/cmem_plugin_base/dataintegration/parameter/graph.py
+++ b/cmem_plugin_base/dataintegration/parameter/graph.py
@@ -1,5 +1,6 @@
 """Knowledge Graph Parameter Type."""
 
+import re
 from typing import Any
 
 from cmem.cmempy.dp.proxy.graph import get_graphs_list
@@ -8,6 +9,8 @@
 from cmem_plugin_base.dataintegration.types import Autocompletion, StringParameterType
 from cmem_plugin_base.dataintegration.utils import setup_cmempy_user_access
 
+IRI_PATTERN = re.compile(r"^[A-Za-z][A-Za-z0-9+.-]*:.+$")
+
 
 class GraphParameterType(StringParameterType):
     """Knowledge Graph parameter type."""
@@ -34,6 +37,8 @@ def __init__(
             - if None -> defaults to di:Dataset, void:Dataset and shui:QueryCatalog
         :param allow_only_autocompleted_values: allow entering new graph URLs
         """
+        self.name = "scheme:string"
+        self._validate_graph()
         self.show_di_graphs = show_di_graphs
         self.show_system_graphs = show_system_graphs
         self.show_graphs_without_class = show_graphs_without_class
@@ -91,3 +96,9 @@ def autocomplete(
                     continue
         result.sort(key=lambda x: x.label)  # type: ignore[return-value, arg-type]
         return list(set(result))
+
+    def _validate_graph(self) -> None:
+        """Verify that graph name is valid aka it has at least a scheme and something after it"""
+        is_valid = bool(IRI_PATTERN.match(self.name))
+        if not is_valid:
+            raise ValueError(f"Could not validate graph IRI '{self.name}'")
diff --git a/poetry.lock b/poetry.lock
index 8e99d9b..2205fc8 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1628,5 +1628,5 @@ zstd = ["backports-zstd (>=1.0.0) ; python_version < \"3.14\""]
 
 [metadata]
 lock-version = "2.1"
-python-versions = "^3.13"
-content-hash = "ad71c832dd08706907ae16d19feb22a8aeb39277e5fc0dc3f66a8819dccb9576"
+python-versions = ">=3.13, ^3"
+content-hash = "6d03f2e04417f3632167c17d1c930d62d1ee61b1512d80e79dc9cff291757777"
diff --git a/pyproject.toml b/pyproject.toml
index 39c5033..30980ca 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,11 +21,12 @@ keywords = [
 homepage = "https://github.com/eccenca/cmem-plugin-base"
 
 [tool.poetry.dependencies]
-python = "^3.13"
-cmem-cmempy = ">=25.2.0"
+python = ">=3.13, ^3"
+cmem-cmempy = "^25.4.0"
 pydantic = "^2.12.2"
 python-ulid = "^3.1.0"
 
+
 [tool.poetry.group.dev.dependencies]
 deptry = "^0.24.0"
 genbadge = {extras = ["coverage"], version = "^1.1.3"}
diff --git a/tests/parameter_types/test_graph.py b/tests/parameter_types/test_graph.py
index 0a29bf9..5432957 100644
--- a/tests/parameter_types/test_graph.py
+++ b/tests/parameter_types/test_graph.py
@@ -1,5 +1,7 @@
 """graph parameter type tests"""
 
+import pytest
+
 from cmem_plugin_base.dataintegration.parameter.graph import GraphParameterType
 from cmem_plugin_base.testing import TestPluginContext
 from tests.utils import needs_cmem
@@ -28,3 +30,29 @@ def test_graph_parameter_type_completion() -> None:
         )
         == 0
     )
+
+
+def test_graph_validation() -> None:
+    """Test graph parameter string validation"""
+    parameter = GraphParameterType(show_system_graphs=True)
+
+    parameter.name = "urn:ISBN:3-8273-7019-1"
+    parameter._validate_graph()  # noqa: SLF001
+
+    parameter.name = "http://test/data"
+    parameter._validate_graph()  # noqa: SLF001
+
+    parameter.name = "https://test/data"
+    parameter._validate_graph()  # noqa: SLF001
+
+    parameter.name = "test :test"
+    with pytest.raises(ValueError, match=f"Could not validate graph IRI '{parameter.name}'"):
+        parameter._validate_graph()  # noqa: SLF001
+
+    parameter.name = ":ttt"
+    with pytest.raises(ValueError, match=f"Could not validate graph IRI '{parameter.name}'"):
+        parameter._validate_graph()  # noqa: SLF001
+
+    parameter.name = ""
+    with pytest.raises(ValueError, match=f"Could not validate graph IRI '{parameter.name}'"):
+        parameter._validate_graph()  # noqa: SLF001