diff --git a/src/economy.c b/src/economy.c
index 6fc1fea60..1cae19b1c 100644
--- a/src/economy.c
+++ b/src/economy.c
@@ -69,6 +69,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 #include <attributes/reduceproduction.h>
 #include <attributes/racename.h>
+#include <spells/regioncurse.h>
 
 /* libs includes */
 #include <math.h>
@@ -2653,14 +2654,10 @@ expandwork(region * r, request * work_begin, request * work_end, int maxwork)
         jobs = rpeasants(r);
     }
     earnings = jobs * p_wage;
-    if (r->attribs && rule_blessed_harvest() == HARVEST_TAXES) {
+    if (jobs > 0 && r->attribs && rule_blessed_harvest() == HARVEST_TAXES) {
         /* E3 rules */
-        const curse_type *blessedharvest_ct = ct_find("blessedharvest");
-        if (blessedharvest_ct) {
-            int happy =
-                (int)(jobs * curse_geteffect(get_curse(r->attribs, blessedharvest_ct)));
-            earnings += happy;
-        }
+        int happy = harvest_effect(r);
+        earnings += happy * jobs;
     }
     rsetmoney(r, money + earnings);
 }
diff --git a/src/kernel/building.c b/src/kernel/building.c
index 14e4a3e07..520807933 100644
--- a/src/kernel/building.c
+++ b/src/kernel/building.c
@@ -55,6 +55,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <limits.h>
 
 /* attributes includes */
+#include <spells/regioncurse.h>
 #include <attributes/reduceproduction.h>
 
 typedef struct building_typelist {
@@ -710,7 +711,7 @@ default_wage(const region * r, const faction * f, const race * rc, int in_turn)
         }
         if (r->attribs && rule_blessed_harvest() == HARVEST_WORK) {
             /* E1 rules */
-            wage += curse_geteffect(get_curse(r->attribs, ct_find("blessedharvest")));
+            wage += harvest_effect(r);
         }
     }
 
diff --git a/src/kernel/curse.c b/src/kernel/curse.c
index 4a3e1c045..336316159 100644
--- a/src/kernel/curse.c
+++ b/src/kernel/curse.c
@@ -596,28 +596,23 @@ curse *create_curse(unit * magician, attrib ** ap, const curse_type * ct,
         if (ct->mergeflags & M_DURATION) {
             c->duration = MAX(c->duration, duration);
         }
-        if (ct->mergeflags & M_SUMDURATION) {
+        else if (ct->mergeflags & M_SUMDURATION) {
             c->duration += duration;
         }
-        if (ct->mergeflags & M_SUMEFFECT) {
-            c->effect += effect;
-        }
         if (ct->mergeflags & M_MAXEFFECT) {
             c->effect = MAX(c->effect, effect);
         }
+        else if (ct->mergeflags & M_SUMEFFECT) {
+            c->effect += effect;
+        }
         if (ct->mergeflags & M_VIGOUR) {
             c->vigour = MAX(vigour, c->vigour);
         }
-        if (ct->mergeflags & M_VIGOUR_ADD) {
+        else if (ct->mergeflags & M_VIGOUR_ADD) {
             c->vigour = vigour + c->vigour;
         }
-        if (ct->mergeflags & M_MEN) {
-            switch (ct->typ) {
-            case CURSETYP_UNIT:
-            {
-                c->data.i += men;
-            }
-            }
+        if (ct->mergeflags & M_MEN && ct->typ == CURSETYP_UNIT) {
+            c->data.i += men;
         }
         set_curseingmagician(magician, *ap, ct);
     }
diff --git a/src/spells/regioncurse.c b/src/spells/regioncurse.c
index b10f3046f..dc9256538 100644
--- a/src/spells/regioncurse.c
+++ b/src/spells/regioncurse.c
@@ -24,6 +24,7 @@
 #include <kernel/unit.h>
 
 /* util includes */
+#include <util/log.h>
 #include <util/nrmessage.h>
 #include <util/message.h>
 #include <util/functions.h>
@@ -33,10 +34,6 @@
 #include <stdlib.h>
 #include <assert.h>
 
-/* --------------------------------------------------------------------- */
-/* CurseInfo mit Spezialabfragen
- */
-
 /*
  * godcursezone
  */
@@ -206,6 +203,22 @@ static struct curse_type ct_blessedharvest = {
     cinfo_simple
 };
 
+int harvest_effect(const struct region *r) {
+    if (r->attribs) {
+        curse *c = get_curse(r->attribs, &ct_blessedharvest);
+        if (c) {
+            int happy = curse_geteffect_int(c);
+            if (happy != 1) {
+                /* https://bugs.eressea.de/view.php?id=2353 detect and fix bad harvest */
+                log_error("blessedharvest curse %d has effect=%d, duration=%d", c->no, happy, c->duration);
+                c->effect = 1.0;
+            }
+            return happy;
+        }
+    }
+    return 0;
+}
+
 static struct curse_type ct_drought = {
     "drought",
     CURSETYP_NORM, 0, (M_DURATION | M_VIGOUR),
diff --git a/src/spells/regioncurse.h b/src/spells/regioncurse.h
index c261ade41..a1ee182c1 100644
--- a/src/spells/regioncurse.h
+++ b/src/spells/regioncurse.h
@@ -17,10 +17,10 @@
 extern "C" {
 #endif
 
-    struct curse;
-    struct locale;
+    struct region;
 
-    extern void register_regioncurse(void);
+    int harvest_effect(const struct region *r);
+    void register_regioncurse(void);
 
 #ifdef __cplusplus
 }