diff --git a/cscripts/csroot2caldb.par b/cscripts/csroot2caldb.par
index 53ff9e9..9dff400 100644
--- a/cscripts/csroot2caldb.par
+++ b/cscripts/csroot2caldb.par
@@ -24,6 +24,8 @@ version,       s, a, prod3,,, "Instrument Response Function version"
 analysis,      s, a, DESY,,, "Instrument Response Function analysis"
 zenith,        r, a, 20.0,0.0,90.0, "Zenith Angle (deg)"
 azimuth,       r, a, 0.0,0.0,360.0, "Azimuth Angle (deg)"
+emin,          r, h, UNDEF,,, "Minimum energy threshold (TeV)"
+emax,          r, h, UNDEF,,, "Maximum energy threshold (TeV)"
 psftype,       s, h, Gauss,Gauss|King,, "Point spread function type"
 split,         b, h, no,,, "Split IRF components into different files"
 norm1d,        b, h, no,,, "Normalize on 1D histograms"
diff --git a/cscripts/csroot2caldb.py b/cscripts/csroot2caldb.py
index 542e86d..1a36e74 100755
--- a/cscripts/csroot2caldb.py
+++ b/cscripts/csroot2caldb.py
@@ -588,6 +588,14 @@ class csroot2caldb(ctools.cscript):
         self._set_cif_keywords(ds['HDU_EA'], irf['EA_NAME'],
                                irf['EA_BOUNDS'], irf['EA_DESC'], irf)
 
+        # Optionally write energy thresholds
+        if self['emin'].is_valid():
+            emin = self['emin'].real()
+            ds['HDU_EA'].card('LO_THRES', emin, '[TeV] Low energy threshold')
+        if self['emax'].is_valid():
+            emin = self['emax'].real()
+            ds['HDU_EA'].card('HI_THRES', emin, '[TeV] High energy threshold')
+
         # Create "EFFAREA" data column
         self._make_2D(etrue, ds['HDU_EA'], 'EFFAREA', 'm2')