diff --git a/src/Fantomas.Tests/KeepIndentInBranchTests.fs b/src/Fantomas.Tests/KeepIndentInBranchTests.fs
index a9e2f2fac5..f407259cc3 100644
--- a/src/Fantomas.Tests/KeepIndentInBranchTests.fs
+++ b/src/Fantomas.Tests/KeepIndentInBranchTests.fs
@@ -1493,3 +1493,50 @@ module Foo =
 
         0
 """
+
+[<Test>]
+let ``multiline if condition is indented, 1729`` () =
+    formatSourceString
+        false
+        """
+let x y =
+            if not (
+                result.HasResultsFor(
+                    [ "label"
+                      "ipv4"
+                      "macAddress"
+                      "medium"
+                      "manufacturer" ]
+                )
+            ) then
+                None
+            else
+
+            let label = string result.["label"]
+            let ipv4 = string result.["ipv4"]
+            None
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let x y =
+    if
+        not (
+            result.HasResultsFor(
+                [ "label"
+                  "ipv4"
+                  "macAddress"
+                  "medium"
+                  "manufacturer" ]
+            )
+        )
+    then
+        None
+    else
+
+    let label = string result.["label"]
+    let ipv4 = string result.["ipv4"]
+    None
+"""
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index ad02d6fa61..2beb447a22 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -5401,9 +5401,24 @@ and genKeepIdentIf
         sepNln
         branches
         (fun idx (ifExpr, thenExpr, _r, _fullRange, _node) ->
-            ifElse (idx = 0) (!- "if ") (!- "elif ")
-            +> genExpr astContext ifExpr
-            +> !- " then"
+            let genIf =
+                let short =
+                    ifElse (idx = 0) (!- "if ") (!- "elif ")
+                    +> genExpr astContext ifExpr
+                    +> !- " then"
+
+                let long =
+                    ifElse (idx = 0) (!- "if ") (!- "elif ")
+                    +> indent
+                    +> sepNln
+                    +> genExpr astContext ifExpr
+                    +> unindent
+                    +> sepNln
+                    +> !- "then"
+
+                expressionFitsOnRestOfLine short long
+
+            genIf
             +> indent
             +> sepNln
             +> genExpr astContext thenExpr