diff --git a/NEWS.md b/NEWS.md
index 125839a46..aaebb00b5 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -35,7 +35,8 @@
   auto-save edits in general (Code -> Saving -> Auto-Save), e.g. on idle editor 
   or focus loss, so this feature becomes less relevant. (#631).
 - blank lines in function calls and headers are now removed, for the former only 
-  when there are no comments before or after the blank line (#629, #630, #635).
+  when there are no comments before or after the blank line (#629, #630, #635, 
+  #723).
 - speed improvements: ~10% when cache is activated because transformers are not 
   captured as character anymore (#679), ~3% in low-level optimization (#691). 
   7% by requiring magrittr 2.0 (#681), ~8% by dropping unused transformers 
diff --git a/R/rules-line-breaks.R b/R/rules-line-breaks.R
index ef9eed84e..9accf76d3 100644
--- a/R/rules-line-breaks.R
+++ b/R/rules-line-breaks.R
@@ -173,7 +173,7 @@ remove_line_break_before_round_closing_after_curly <- function(pd) {
 
 remove_line_breaks_in_fun_dec <- function(pd) {
   if (is_function_dec(pd)) {
-    round_after <- pd$token == "')'" & pd$token_before != "COMMENT"
+    round_after <- (pd$token == "')'" | pd$token_before == "'('") & pd$token_before != "COMMENT"
     pd$lag_newlines[pd$lag_newlines > 1L] <- 1L
     pd$lag_newlines[round_after] <- 0L
   }
diff --git a/tests/testthat/fun_dec/line_break_fun_dec-in.R b/tests/testthat/fun_dec/line_break_fun_dec-in.R
index a72d9d215..4bf36e4ac 100644
--- a/tests/testthat/fun_dec/line_break_fun_dec-in.R
+++ b/tests/testthat/fun_dec/line_break_fun_dec-in.R
@@ -33,3 +33,16 @@ a <- function(x,
               y) {
   x - 1
 }
+
+
+a <- function(
+              x,
+              y) {
+  x - 1
+}
+
+a <- function( #
+  x,
+  y) {
+  x - 1
+}
diff --git a/tests/testthat/fun_dec/line_break_fun_dec-in_tree b/tests/testthat/fun_dec/line_break_fun_dec-in_tree
index 7ffbd33fd..4c1378941 100644
--- a/tests/testthat/fun_dec/line_break_fun_dec-in_tree
+++ b/tests/testthat/fun_dec/line_break_fun_dec-in_tree
@@ -102,24 +102,67 @@ ROOT (token: short_text [lag_newlines/spaces] {pos_id})
  ¦           ¦   °--expr: 1 [0/0] {97}                 
  ¦           ¦       °--NUM_CONST: 1 [0/0] {96}        
  ¦           °--'}': } [1/0] {98}                      
- °--expr: a <-  [2/0] {99}                             
-     ¦--expr: a [0/1] {101}                            
-     ¦   °--SYMBOL: a [0/0] {100}                      
-     ¦--LEFT_ASSIGN: <- [0/1] {102}                    
-     °--expr: funct [0/0] {103}                        
-         ¦--FUNCTION: funct [0/0] {104}                
-         ¦--'(': ( [0/0] {105}                         
-         ¦--SYMBOL_FORMALS: x [0/0] {106}              
-         ¦--',': , [0/14] {107}                        
-         ¦--SYMBOL_FORMALS: y [2/0] {108}              
-         ¦--')': ) [0/1] {109}                         
-         °--expr: {
+ ¦--expr: a <-  [2/0] {99}                             
+ ¦   ¦--expr: a [0/1] {101}                            
+ ¦   ¦   °--SYMBOL: a [0/0] {100}                      
+ ¦   ¦--LEFT_ASSIGN: <- [0/1] {102}                    
+ ¦   °--expr: funct [0/0] {103}                        
+ ¦       ¦--FUNCTION: funct [0/0] {104}                
+ ¦       ¦--'(': ( [0/0] {105}                         
+ ¦       ¦--SYMBOL_FORMALS: x [0/0] {106}              
+ ¦       ¦--',': , [0/14] {107}                        
+ ¦       ¦--SYMBOL_FORMALS: y [2/0] {108}              
+ ¦       ¦--')': ) [0/1] {109}                         
+ ¦       °--expr: {
   x [0/0] {110}                   
-             ¦--'{': { [0/2] {111}                     
-             ¦--expr: x - 1 [1/0] {112}                
-             ¦   ¦--expr: x [0/1] {114}                
-             ¦   ¦   °--SYMBOL: x [0/0] {113}          
-             ¦   ¦--'-': - [0/1] {115}                 
-             ¦   °--expr: 1 [0/0] {117}                
-             ¦       °--NUM_CONST: 1 [0/0] {116}       
-             °--'}': } [1/0] {118}                     
+ ¦           ¦--'{': { [0/2] {111}                     
+ ¦           ¦--expr: x - 1 [1/0] {112}                
+ ¦           ¦   ¦--expr: x [0/1] {114}                
+ ¦           ¦   ¦   °--SYMBOL: x [0/0] {113}          
+ ¦           ¦   ¦--'-': - [0/1] {115}                 
+ ¦           ¦   °--expr: 1 [0/0] {117}                
+ ¦           ¦       °--NUM_CONST: 1 [0/0] {116}       
+ ¦           °--'}': } [1/0] {118}                     
+ ¦--expr: a <-  [3/0] {119}                            
+ ¦   ¦--expr: a [0/1] {121}                            
+ ¦   ¦   °--SYMBOL: a [0/0] {120}                      
+ ¦   ¦--LEFT_ASSIGN: <- [0/1] {122}                    
+ ¦   °--expr: funct [0/0] {123}                        
+ ¦       ¦--FUNCTION: funct [0/0] {124}                
+ ¦       ¦--'(': ( [0/14] {125}                        
+ ¦       ¦--SYMBOL_FORMALS: x [1/0] {126}              
+ ¦       ¦--',': , [0/14] {127}                        
+ ¦       ¦--SYMBOL_FORMALS: y [1/0] {128}              
+ ¦       ¦--')': ) [0/1] {129}                         
+ ¦       °--expr: {
+  x [0/0] {130}                   
+ ¦           ¦--'{': { [0/2] {131}                     
+ ¦           ¦--expr: x - 1 [1/0] {132}                
+ ¦           ¦   ¦--expr: x [0/1] {134}                
+ ¦           ¦   ¦   °--SYMBOL: x [0/0] {133}          
+ ¦           ¦   ¦--'-': - [0/1] {135}                 
+ ¦           ¦   °--expr: 1 [0/0] {137}                
+ ¦           ¦       °--NUM_CONST: 1 [0/0] {136}       
+ ¦           °--'}': } [1/0] {138}                     
+ °--expr: a <-  [2/0] {139}                            
+     ¦--expr: a [0/1] {141}                            
+     ¦   °--SYMBOL: a [0/0] {140}                      
+     ¦--LEFT_ASSIGN: <- [0/1] {142}                    
+     °--expr: funct [0/0] {143}                        
+         ¦--FUNCTION: funct [0/0] {144}                
+         ¦--'(': ( [0/1] {145}                         
+         ¦--COMMENT: # [0/2] {146}                     
+         ¦--SYMBOL_FORMALS: x [1/0] {147}              
+         ¦--',': , [0/2] {148}                         
+         ¦--SYMBOL_FORMALS: y [1/0] {149}              
+         ¦--')': ) [0/1] {150}                         
+         °--expr: {
+  x [0/0] {151}                   
+             ¦--'{': { [0/2] {152}                     
+             ¦--expr: x - 1 [1/0] {153}                
+             ¦   ¦--expr: x [0/1] {155}                
+             ¦   ¦   °--SYMBOL: x [0/0] {154}          
+             ¦   ¦--'-': - [0/1] {156}                 
+             ¦   °--expr: 1 [0/0] {158}                
+             ¦       °--NUM_CONST: 1 [0/0] {157}       
+             °--'}': } [1/0] {159}                     
diff --git a/tests/testthat/fun_dec/line_break_fun_dec-out.R b/tests/testthat/fun_dec/line_break_fun_dec-out.R
index 42f87027c..81aff8516 100644
--- a/tests/testthat/fun_dec/line_break_fun_dec-out.R
+++ b/tests/testthat/fun_dec/line_break_fun_dec-out.R
@@ -32,3 +32,15 @@ a <- function(x,
               y) {
   x - 1
 }
+
+
+a <- function(x,
+              y) {
+  x - 1
+}
+
+a <- function( #
+              x,
+              y) {
+  x - 1
+}