diff --git a/src/substrait/__init__.py b/src/substrait/__init__.py
index e3005c5..9f3ff02 100644
--- a/src/substrait/__init__.py
+++ b/src/substrait/__init__.py
@@ -3,6 +3,6 @@
 except ImportError:
     pass
 
-__substrait_version__ = "0.43.0"
-__substrait_hash__ = "5e1948e"
+__substrait_version__ = "0.44.0"
+__substrait_hash__ = "2e12da1"
 __minimum_substrait_version__ = "0.30.0"
diff --git a/src/substrait/extensions/functions_logarithmic.yaml b/src/substrait/extensions/functions_logarithmic.yaml
index f4b8acc..fc88dab 100644
--- a/src/substrait/extensions/functions_logarithmic.yaml
+++ b/src/substrait/extensions/functions_logarithmic.yaml
@@ -12,7 +12,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp32
@@ -23,7 +23,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp64
@@ -38,7 +38,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp32
@@ -49,7 +49,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp64
@@ -64,7 +64,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp32
@@ -75,7 +75,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp64
@@ -97,7 +97,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp32
@@ -112,7 +112,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp64
@@ -130,7 +130,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp32
@@ -141,7 +141,7 @@ scalar_functions:
           rounding:
             values: [ TIE_TO_EVEN, TIE_AWAY_FROM_ZERO, TRUNCATE, CEILING, FLOOR ]
           on_domain_error:
-            values: [ NAN, ERROR ]
+            values: [ NAN, "NULL", ERROR ]
           on_log_zero:
             values: [NAN, ERROR, MINUS_INFINITY]
         return: fp64
diff --git a/src/substrait/extensions/functions_string.yaml b/src/substrait/extensions/functions_string.yaml
index 3e5d496..2e0f174 100644
--- a/src/substrait/extensions/functions_string.yaml
+++ b/src/substrait/extensions/functions_string.yaml
@@ -3,19 +3,30 @@
 scalar_functions:
   -
     name: concat
-    description: Concatenate strings.
+    description: >-
+      Concatenate strings.
+
+      The `null_handling` option determines whether or not null values will be recognized by the function.
+      If `null_handling` is set to `IGNORE_NULLS`, null value arguments will be ignored when strings are concatenated.
+      If set to `ACCEPT_NULLS`, the result will be null if any argument passed to the concat function is null.
     impls:
       - args:
           - value: "varchar<L1>"
             name: "input"
         variadic:
           min: 1
+        options:
+          null_handling:
+            values: [ IGNORE_NULLS, ACCEPT_NULLS ]
         return: "varchar<L1>"
       - args:
           - value: "string"
             name: "input"
         variadic:
           min: 1
+        options:
+          null_handling:
+            values: [ IGNORE_NULLS, ACCEPT_NULLS ]
         return: "string"
   -
     name: like
diff --git a/third_party/substrait b/third_party/substrait
index 5e1948e..2e12da1 160000
--- a/third_party/substrait
+++ b/third_party/substrait
@@ -1 +1 @@
-Subproject commit 5e1948e7a9e945d347b011e6518d1bb501f8522a
+Subproject commit 2e12da1b9915eea01f12ece0be9c37afa1384f74