diff --git a/tools/map_param_value/map_param_value.xml b/tools/map_param_value/map_param_value.xml
index 64cb933b0dd..2ff2159b116 100644
--- a/tools/map_param_value/map_param_value.xml
+++ b/tools/map_param_value/map_param_value.xml
@@ -107,6 +107,56 @@ return { output: coerceToOutput(source) };
         </output>
     </outputs>
     <tests>
+        <test expect_num_outputs="1">
+            <!-- map empty string to False and True as Fallback: null -> true -->
+            <conditional name="input_param_type">
+                <param name="input_param" value_json="null" />
+                <repeat name="mappings">
+                    <param name="from" value="" />
+                    <param name="to" value="False" />
+                </repeat>
+            </conditional>
+            <conditional name="unmapped">
+                <param name="on_unmapped" value="default"/>
+                <param name="default_value" value="True"/>
+            </conditional>
+            <param name="output_param_type" value="boolean"/>
+            <output name="output_param_boolean" value_json="true" />
+        </test>
+
+        <test expect_num_outputs="1">
+            <!-- map empty string to False and True as Fallback: "" -> false -->
+            <conditional name="input_param_type">
+                <param name="input_param" value="" />
+                <repeat name="mappings">
+                    <param name="from" value="" />
+                    <param name="to" value="False" />
+                </repeat>
+            </conditional>
+            <conditional name="unmapped">
+                <param name="on_unmapped" value="default"/>
+                <param name="default_value" value="True"/>
+            </conditional>
+            <param name="output_param_type" value="boolean"/>
+            <output name="output_param_boolean" value_json="false" />
+        </test>
+
+        <test expect_num_outputs="1">
+            <!-- map default of optional string (from not specifies) to False and True as Fallback: "" -> true, i.e. default of optional string parameter is null -->
+            <conditional name="input_param_type">
+                <param name="input_param" value="" />
+                <repeat name="mappings">
+                    <param name="to" value="False" />
+                </repeat>
+            </conditional>
+            <conditional name="unmapped">
+                <param name="on_unmapped" value="default"/>
+                <param name="default_value" value="True"/>
+            </conditional>
+            <param name="output_param_type" value="boolean"/>
+            <output name="output_param_boolean" value_json="true" />
+        </test>
+
         <test expect_num_outputs="1">
             <!-- map string A to string B -->
             <conditional name="input_param_type">