diff --git a/snakemake_executor_plugin_slurm/utils.py b/snakemake_executor_plugin_slurm/utils.py
index 97df1faf..2cd5a0be 100644
--- a/snakemake_executor_plugin_slurm/utils.py
+++ b/snakemake_executor_plugin_slurm/utils.py
@@ -251,8 +251,9 @@ def set_gres_string(job: JobExecutorInterface) -> str:
     based on the resources requested in the job.
     """
     # generic resources (GRES) arguments can be of type
-    # "string:int" or "string:string:int"
-    gres_re = re.compile(r"^[a-zA-Z0-9_]+(:[a-zA-Z0-9_\.]+)?:\d+$")
+    # "string:int" or "string:string:int" with optional postfix 'T' or 'G' or 'M'
+    gres_re = re.compile(r"^[a-zA-Z0-9_]+(:[a-zA-Z0-9_\.]+)?:\d+[TGM]?$")
+
     # gpu model arguments can be of type "string"
     # The model string may contain a dot for variants, see
     # https://github.com/snakemake/snakemake-executor-plugin-slurm/issues/387
@@ -288,14 +289,16 @@ def set_gres_string(job: JobExecutorInterface) -> str:
                     "GRES format should not be a nested string (start "
                     "and end with ticks or quotation marks). "
                     "Expected format: "
-                    "'<name>:<number>' or '<name>:<type>:<number>' "
+                    "'<name>:<number>' or '<name>:<type>:<number>' with an optional "
+                    "'T' 'M' or 'G' postfix "
                     "(e.g., 'gpu:1' or 'gpu:tesla:2')"
                 )
             else:
                 raise WorkflowError(
                     f"Invalid GRES format: {gres}. Expected format: "
-                    "'<name>:<number>' or '<name>:<type>:<number>' "
-                    "(e.g., 'gpu:1' or 'gpu:tesla:2')"
+                    "'<name>:<number>' or '<name>:<type>:<number>' with an optional "
+                    "'T' 'M' or 'G' postfix "
+                    "(e.g., 'gpu:1' or 'gpu:tesla:2') "
                 )
         return f" --gres={job.resources.gres}"
 
diff --git a/tests/tests.py b/tests/tests.py
index 301b2742..06c7bee6 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -368,6 +368,20 @@ def test_gpu_model_without_gpu(self, mock_job):
             ):
                 set_gres_string(job)
 
+    def test_tmpspace_gres_10G(self, mock_job):
+        """Test with valid GRES format (simple)."""
+        job = mock_job(gres="tmpspace:10G")
+
+        # Patch subprocess.Popen to capture the sbatch command
+        with patch("subprocess.Popen") as mock_popen:
+            # Configure the mock to return successful submission
+            process_mock = MagicMock()
+            process_mock.communicate.return_value = ("123", "")
+            process_mock.returncode = 0
+            mock_popen.return_value = process_mock
+
+        assert set_gres_string(job) == " --gres=tmpspace:10G"
+
     def test_both_gres_and_gpu_set(self, mock_job):
         """Test error case when both GRES and GPU are specified."""
         job = mock_job(gres="gpu:1", gpu="2")