diff --git a/udapi/block/msf/phrase.py b/udapi/block/msf/phrase.py
index 6c5c587a..c92e5e91 100644
--- a/udapi/block/msf/phrase.py
+++ b/udapi/block/msf/phrase.py
@@ -59,6 +59,8 @@ def get_polarity(self, node, neg):
         return 'Neg'
 		
     def get_is_reflex(self,node,refl):
+        if node.feats['Voice'] == 'Mid':
+            return 'Yes'
         if len(refl) == 0:
             return node.feats['Reflex']
         return 'Yes'
diff --git a/udapi/block/msf/slavic/past.py b/udapi/block/msf/slavic/past.py
index 34dcd354..d4f3c7cd 100644
--- a/udapi/block/msf/slavic/past.py
+++ b/udapi/block/msf/slavic/past.py
@@ -39,7 +39,7 @@ def process_node(self, node):
 						person=node.feats['Person'],
 						number=node.feats['Number'],
 						mood=node.feats['Mood'],
-						voice='Pass',
+						voice='Act', #In Polish, impersonal statements are annotated with Voice=Act. In Ukrainian, the Voice feature is missing; therefore, we decided to annotate these phrases with PhraseVoice=Act
 						aspect=node.feats['Aspect'],
 						form=node.feats['VerbForm'],
 						polarity=self.get_polarity(node,neg),
diff --git a/udapi/block/msf/slavic/preprocessor.py b/udapi/block/msf/slavic/preprocessor.py
index 5d090a2c..e9a5e90b 100644
--- a/udapi/block/msf/slavic/preprocessor.py
+++ b/udapi/block/msf/slavic/preprocessor.py
@@ -31,8 +31,7 @@ def process_node(self,node):
 		# In Ukrainian, there is no explicit annotation of reflexive verbs
 		# We decided to unify the annotation of reflexive verbs with Russian and Belarusian, where reflexive verbs are formed similarly
 		# We add the feature Voice=Mid to reflexive verbs
-		# This feature is added only to Ukrainian data (for example, there are some verbs in Old Church Slavonic that end in 'сь' but are not reflexive)
-		if node.upos == 'VERB' and (node.form.endswith('сь') or node.form.endswith('ся')) and self.lang == 'uk':
+		if node.upos == 'VERB' and (node.lemma.endswith('сь') or node.lemma.endswith('ся')):
 			node.feats['Voice'] = 'Mid'
 		
 		# makedonstina tvori budouci cas pomoci pomocneho slova ќе, u nejz neni nijak vyznaceno, ze se podili na tvorbe budouciho casu
@@ -72,5 +71,9 @@ def process_node(self,node):
 		if node.feats['Mood'] == 'Sub':
 			node.feats['Mood'] = 'Cnd'
 
+		# # although infinitives in Old Church Slavonic are annotated with Tense=Pres, they do not convey tense; therefore, we remove this annotation
+		if node.feats['VerbForm'] == 'Inf':
+			node.feats['Tense'] = ''
+
 		# TODO maybe we want to set Tense=Fut for the perfective verbs with Tense=Pres? This could solve the problem with the simplified detection of the future tense in Czech
 		# but there are many verbs with no Aspect value, so the problem is still there