diff --git a/changes/9.0.1.md b/changes/9.0.1.md
index 75643b463..7fb714838 100644
--- a/changes/9.0.1.md
+++ b/changes/9.0.1.md
@@ -1,2 +1,3 @@
  * Fix serifs in dingbat circled numbers (#1182).
- * Fix broken shape of Latin Letter Tone Five (Regression, #1074).
\ No newline at end of file
+ * Fix broken shape of Latin Letter Tone Five (Regression, #1074).
+ * Fix broken serif of iotified capital Cyrillic letters (#1184).
\ No newline at end of file
diff --git a/font-src/glyphs/letter/cyrillic/big-yus.ptl b/font-src/glyphs/letter/cyrillic/big-yus.ptl
index c9a6e8ad4..a1c9bae25 100644
--- a/font-src/glyphs/letter/cyrillic/big-yus.ptl
+++ b/font-src/glyphs/letter/cyrillic/big-yus.ptl
@@ -63,7 +63,7 @@ glyph-block Letter-Cyrillic-BigYus : begin
 		include : df.markSet.e
 		include : CyrBigYusShape df XH 0.55
 
-	define [CyrIotifiedBigYusShape df top yp] : glyph-proc
+	define [CyrIotifiedBigYusShape fCapital df top yp] : glyph-proc
 		local gap : (df.width - 2 * df.leftSB - 4 * df.mvs) / 3
 		define divSub : (df.width - gap - df.mvs) / Width
 		define dfSub : DivFrame divSub 3
@@ -76,17 +76,18 @@ glyph-block Letter-Cyrillic-BigYus : begin
 		include : HBarTop (df.leftSB - O) [mix df.leftSB df.rightSB (2 / 3)] (top * yp) df.mvs
 		if SLAB : begin
 			include : tagged 'serifLT' : LeftwardTopSerif df.leftSB top SideJut df.mvs
-			if [not para.isItalic] : include : tagged 'serifLB' : LeftwardBottomSerif df.leftSB 0 SideJut df.mvs
+			if (fCapital || [not para.isItalic]) : begin
+				include : tagged 'serifLB' : LeftwardBottomSerif df.leftSB 0 SideJut df.mvs
 			include : tagged 'serifRB' : RightwardBottomSerif (df.rightSB + 0.5 * df.mvs * HVContrast) 0 (SideJut - 0.5 * df.mvs * HVContrast) df.mvs
 
 	create-glyph 'cyrl/BigYusIotified' 0x46C : glyph-proc
 		local df : DivFrame para.diversityM 4
 		set-width df.width
 		include : df.markSet.capital
-		include : CyrIotifiedBigYusShape df CAP 0.575
+		include : CyrIotifiedBigYusShape true df CAP 0.575
 
 	create-glyph 'cyrl/bigYusIotified' 0x46D : glyph-proc
 		local df : DivFrame para.diversityM 4
 		set-width df.width
 		include : df.markSet.e
-		include : CyrIotifiedBigYusShape df XH 0.55
\ No newline at end of file
+		include : CyrIotifiedBigYusShape false df XH 0.55
\ No newline at end of file
diff --git a/font-src/glyphs/letter/cyrillic/small-yus.ptl b/font-src/glyphs/letter/cyrillic/small-yus.ptl
index 9bf590b20..bfa94bc15 100644
--- a/font-src/glyphs/letter/cyrillic/small-yus.ptl
+++ b/font-src/glyphs/letter/cyrillic/small-yus.ptl
@@ -41,7 +41,7 @@ glyph-block Letter-Cyrillic-SmallYus : begin
 	select-variant 'cyrl/SmallYus' 0x466 (follow -- 'grek/Lambda')
 	select-variant 'cyrl/smallYus' 0x467 (follow -- 'grek/Lambda')
 
-	define [CyrIotifiedSmallYusShape df top straightBar] : glyph-proc
+	define [CyrIotifiedSmallYusShape fCapital df top straightBar] : glyph-proc
 		local gap : (df.width - 2 * df.leftSB - 4 * df.mvs) / 3
 		define divSub : (df.width - gap - df.mvs) / Width
 		define dfSub : DivFrame divSub 3
@@ -53,25 +53,30 @@ glyph-block Letter-Cyrillic-SmallYus : begin
 		include : VBarLeft df.leftSB 0 top df.mvs
 		include : HBarTop (df.leftSB - O) [mix df.leftSB df.rightSB (2 / 3)] (top / 2) df.mvs
 		if SLAB : begin
-			include : tagged 'serifLT' : if para.isItalic
+			include : tagged 'serifLT' : if (!fCapital && para.isItalic)
 				LeftwardTopSerif df.leftSB top SideJut df.mvs
 				CenterTopSerif (df.leftSB + 0.5 * df.mvs * HVContrast) top Jut df.mvs
-			if [not para.isItalic] : include : tagged 'serifLB' : LeftwardBottomSerif df.leftSB 0 SideJut df.mvs
+			if (fCapital || [not para.isItalic]) : begin
+				include : tagged 'serifLB' : LeftwardBottomSerif df.leftSB 0 SideJut df.mvs
 			include : tagged 'serifRB' : RightwardBottomSerif df.rightSB 0 SideJut df.mvs
 
 	create-glyph : glyph-proc
 		local df : DivFrame para.diversityM 4
 		set-width df.width
 		include : df.markSet.capital
-		create-forked-glyph 'cyrl/IotifiedSmallYus.straight' : CyrIotifiedSmallYusShape df CAP true
-		create-forked-glyph 'cyrl/IotifiedSmallYus.curly' : CyrIotifiedSmallYusShape df CAP false
+		create-forked-glyph 'cyrl/IotifiedSmallYus.straight'
+			CyrIotifiedSmallYusShape true df CAP true
+		create-forked-glyph 'cyrl/IotifiedSmallYus.curly'
+			CyrIotifiedSmallYusShape true df CAP false
 
 	create-glyph : glyph-proc
 		local df : DivFrame para.diversityM 4
 		set-width df.width
 		include : df.markSet.e
-		create-forked-glyph 'cyrl/iotifiedSmallYus.straight' : CyrIotifiedSmallYusShape df XH true
-		create-forked-glyph 'cyrl/iotifiedSmallYus.curly' : CyrIotifiedSmallYusShape df XH false
+		create-forked-glyph 'cyrl/iotifiedSmallYus.straight'
+			CyrIotifiedSmallYusShape false df XH true
+		create-forked-glyph 'cyrl/iotifiedSmallYus.curly'
+			CyrIotifiedSmallYusShape false df XH false
 
 	select-variant 'cyrl/IotifiedSmallYus' 0x468 (follow -- 'grek/Lambda')
 	select-variant 'cyrl/iotifiedSmallYus' 0x469 (follow -- 'grek/Lambda')
diff --git a/font-src/glyphs/letter/latin/c.ptl b/font-src/glyphs/letter/latin/c.ptl
index fc7285665..9a4952c23 100644
--- a/font-src/glyphs/letter/latin/c.ptl
+++ b/font-src/glyphs/letter/latin/c.ptl
@@ -219,7 +219,7 @@ glyph-block Letter-Latin-C : begin
 			include : AutoStartSerifR [DivFrame 1] sty XH
 			include : AutoStartSerifRB [DivFrame 1] styBot Descender
 
-		define [IotifiedEsShape df top sma smb] : glyph-proc
+		define [IotifiedEsShape fCapital df top sma smb] : glyph-proc
 			local gap : (df.width - 2 * df.leftSB - 2.5 * df.mvs) * 0.375
 			define divSub : (df.width - gap - df.mvs) / Width
 			define dfSub : DivFrame divSub 2
@@ -234,22 +234,24 @@ glyph-block Letter-Latin-C : begin
 				local sf : SerifFrame top 0 df.leftSB df.rightSB df.mvs
 				if (df.width > para.refJut * 7) : begin
 					include : tagged 'serifLT' sf.lt.full
-					if [not para.isItalic] : include : tagged 'serifLB' sf.lb.full
+					if (fCapital || [not para.isItalic]) : begin
+						include : tagged 'serifLB' sf.lb.full
 				: else : begin
 					include : tagged 'serifLT' sf.lt.outer
-					if [not para.isItalic] : include : tagged 'serifLB' sf.lb.outer
+					if (fCapital || [not para.isItalic]) : begin
+						include : tagged 'serifLB' sf.lb.outer
 
 		create-glyph "cyrl/iotified{E}.\(suffix)" : glyph-proc
 			local df : DivFrame para.diversityM 2.5
 			set-width df.width
 			include : df.markSet.capital
-			include : IotifiedEsShape df CAP SmoothA SmoothB
+			include : IotifiedEsShape true df CAP SmoothA SmoothB
 
 		create-glyph "cyrl/iotified{e}.\(suffix)" : glyph-proc
 			local df : DivFrame para.diversityM 2.5
 			set-width df.width
 			include : df.markSet.e
-			include : IotifiedEsShape df XH SmallSmoothA SmallSmoothB
+			include : IotifiedEsShape false df XH SmallSmoothA SmallSmoothB
 
 	select-variant 'C' 'C'
 	link-reduced-variant 'C/sansSerif' 'C' MathSansSerif