diff --git a/RELNOTES b/RELNOTES
index cc70b866..c48e36f9 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -50,6 +50,8 @@ work on other platforms. Please report any problems and suggested fixes to
 
 			Changes since 4.1.0a1
 
+- Fixed a coredump when adding a class via OMAPI.
+
 - Check whether files are zero length before trying to parse them.
 
 - Ari Edelkind's PARANOIA patch has been included and may be compiled in
diff --git a/server/omapi.c b/server/omapi.c
index 4420e81d..4cc5a689 100644
--- a/server/omapi.c
+++ b/server/omapi.c
@@ -1869,11 +1869,10 @@ class_set_value (omapi_object_t *h,
 			if (!strncmp("hardware",
 				     (char *)value->u.buffer.value, minlen))
 			{
-				if (!expression_allocate(&class->submatch,
-							 MDL))
+				if (!expression_allocate(&class->submatch, MDL))
 					return ISC_R_NOMEMORY;
 
-				class->expr->op = expr_hardware;
+				class->submatch->op = expr_hardware;
 			} else
 				return ISC_R_INVALIDARG;
 		} else