diff --git a/src/Val.cc b/src/Val.cc
index 8d0fbdf499..965ea3d026 100644
--- a/src/Val.cc
+++ b/src/Val.cc
@@ -2883,7 +2883,7 @@ RecordVal::~RecordVal()
 
 void RecordVal::Assign(int field, Val* new_val, Opcode op)
 	{
-	if ( Lookup(field) &&
+	if ( new_val && Lookup(field) &&
 	     record_type->FieldType(field)->Tag() == TYPE_TABLE &&
 	     new_val->AsTableVal()->FindAttr(ATTR_MERGEABLE) )
 		{
diff --git a/testing/btest/Baseline/language.delete-field-set/output b/testing/btest/Baseline/language.delete-field-set/output
new file mode 100644
index 0000000000..ccf6dbc793
--- /dev/null
+++ b/testing/btest/Baseline/language.delete-field-set/output
@@ -0,0 +1 @@
+[a=<uninitialized>, b=<uninitialized>, c=<uninitialized>]
diff --git a/testing/btest/language/delete-field-set.bro b/testing/btest/language/delete-field-set.bro
new file mode 100644
index 0000000000..9469dbb2f0
--- /dev/null
+++ b/testing/btest/language/delete-field-set.bro
@@ -0,0 +1,17 @@
+
+# @TEST-EXEC: bro %INPUT >output 2>&1
+# @TEST-EXEC: btest-diff output
+
+type FooBar: record {
+        a: set[string] &default=set();
+        b: table[string] of count &default=table();
+        c: vector of string &default=vector();
+};
+
+global test: FooBar;
+
+delete test$a;
+delete test$b;
+delete test$c;
+
+print test;