diff --git a/fmriprep/workflows/bold/base.py b/fmriprep/workflows/bold/base.py
index 95c432db2..d5e6a3581 100644
--- a/fmriprep/workflows/bold/base.py
+++ b/fmriprep/workflows/bold/base.py
@@ -564,7 +564,7 @@ def init_func_preproc_wf(bold_file, has_fieldmap=False):
         # create optimal combination, adaptive T2* map
         bold_t2s_wf = init_bold_t2s_wf(
             echo_times=tes,
-            mem_gb=mem_gb["resampled"],
+            mem_gb=mem_gb["filesize"],
             omp_nthreads=omp_nthreads,
             name="bold_t2smap_wf",
         )
diff --git a/fmriprep/workflows/bold/t2s.py b/fmriprep/workflows/bold/t2s.py
index 951046c5a..e56d0e754 100644
--- a/fmriprep/workflows/bold/t2s.py
+++ b/fmriprep/workflows/bold/t2s.py
@@ -98,7 +98,11 @@ def init_bold_t2s_wf(echo_times, mem_gb, omp_nthreads, name='bold_t2s_wf'):
 
     LOGGER.log(25, 'Generating T2* map and optimally combined ME-EPI time series.')
 
-    t2smap_node = pe.Node(T2SMap(echo_times=list(echo_times)), name='t2smap_node')
+    t2smap_node = pe.Node(
+        T2SMap(echo_times=list(echo_times)),
+        name='t2smap_node',
+        mem_gb=2 * mem_gb * len(echo_times),
+    )
     # fmt:off
     workflow.connect([
         (inputnode, t2smap_node, [('bold_file', 'in_files'),