diff --git a/dictsource/vi_rules b/dictsource/vi_rules
index e6d86698..1ed6363b 100644
--- a/dictsource/vi_rules
+++ b/dictsource/vi_rules
@@ -713,12 +713,12 @@ ỵ	ỵ
         iủ         iU4
         iũ         iU5
         iụ         iU6
-        iêu        iU
-        iều        iU2
-        iếu        iU3
-        iểu        iU4
-        iễu        iU5
-        iệu        iU6
+        iêu        iEw
+        iều        iEw2
+        iếu        iEw3
+        iểu        iEw4
+        iễu        iEw5
+        iệu        iEw6
         i (L01     _^_EN
         i (@       _^_EN
 ?2      i (L03     @         
diff --git a/phsource/ph_vietnam b/phsource/ph_vietnam
index db73f0f9..58cb6180 100644
--- a/phsource/ph_vietnam
+++ b/phsource/ph_vietnam
@@ -768,6 +768,7 @@ endphoneme
 phoneme p
   vls blb stp
     lengthmod 2
+	length 15
   Vowelin  f1=0  f2=1000 -50 -100  f3=-200 80 amp=11
   Vowelout f1=0  f2=1000 -500 -350  f3=-300 80 rms=22
 
@@ -780,7 +781,7 @@ phoneme t[        // dental variant of /t/
 	vls alv stp
 	voicingswitch d
 	lengthmod 2
-	length 5
+	length 15
 	Vowelin f1=1  f2=1500 -250 250  f3=-100 80  amp=16 len=15
 	Vowelout f1=0 f2=1500 -300 250  f3=-100 80  rms=20 len=15
 	WAV(ustop/t, 50)
@@ -788,7 +789,7 @@ phoneme t[        // dental variant of /t/
 	vls dnt stp
 	voicingswitch d[
 	lengthmod 2
-	length 5
+	length 15
 	Vowelin f1=1  f2=1500 -250 250  f3=-100 80  amp=16 len=15
 	Vowelout f1=0 f2=1500 -300 250  f3=-100 80  rms=20 len=15