diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2e5e318..2d43fc7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,14 +10,11 @@ The format is based on `Keep a Changelog (http://keepachangelog.com/en/1.0.0/) <
 
 * Added a configuration file schema ``FmuImporterConfiguration.schema.json`` for FmuImporter and included it in release package and extended documentation how to use it.
 
----
-
-## [1.2.0] - TBD
-
 ### Fixed
 
 * Fixed configuration of boolean parameters via config file
-* The importer did not run with an 'autonomous' lifecycle if the time synchronization mode was set to 'unsynchronized' - this is now working as intended.
+* The importer did not run with an 'autonomous' lifecycle if the time synchronization mode was set to 'unsynchronized' - this is now working as intended
+* Fixed a crash that occurred if an FMU's model description had a unit definition that did not use a base unit
 
 ---
 
diff --git a/FmuImporter/FmiBridge/FmiModel/Internal/ModelDescription.cs b/FmuImporter/FmiBridge/FmiModel/Internal/ModelDescription.cs
index 0d1e7cd..6f53093 100644
--- a/FmuImporter/FmiBridge/FmiModel/Internal/ModelDescription.cs
+++ b/FmuImporter/FmiBridge/FmiModel/Internal/ModelDescription.cs
@@ -223,11 +223,15 @@ private void InitUnitMap(Fmi3.fmiModelDescriptionUnitDefinitions input)
     {
       var unitDefinition = new UnitDefinition
       {
-        Name = fmi3Unit.name,
-        Offset = fmi3Unit.BaseUnit.offset,
-        Factor = fmi3Unit.BaseUnit.factor
+        Name = fmi3Unit.name
       };
 
+      if (fmi3Unit.BaseUnit != null)
+      {
+        unitDefinition.Offset = fmi3Unit.BaseUnit.offset;
+        unitDefinition.Factor = fmi3Unit.BaseUnit.factor;
+      }
+
       UnitDefinitions.Add(unitDefinition.Name, unitDefinition);
     }
   }
@@ -239,15 +243,19 @@ private void InitUnitMap(Fmi2.fmiModelDescriptionUnitDefinitions input)
       return;
     }
 
-    foreach (var fmi3Unit in input.Unit)
+    foreach (var fmi2Unit in input.Unit)
     {
       var unitDefinition = new UnitDefinition
       {
-        Name = fmi3Unit.name,
-        Offset = fmi3Unit.BaseUnit.offset,
-        Factor = fmi3Unit.BaseUnit.factor
+        Name = fmi2Unit.name
       };
 
+      if (fmi2Unit.BaseUnit != null)
+      {
+        unitDefinition.Offset = fmi2Unit.BaseUnit.offset;
+        unitDefinition.Factor = fmi2Unit.BaseUnit.factor;
+      }
+
       UnitDefinitions.Add(unitDefinition.Name, unitDefinition);
     }
   }