diff --git a/awx/main/models/inventory.py b/awx/main/models/inventory.py
index beeb5ec878..734cd002f8 100644
--- a/awx/main/models/inventory.py
+++ b/awx/main/models/inventory.py
@@ -724,10 +724,11 @@ class InventoryUpdate(UnifiedJob, InventorySourceOptions):
         return reverse('api:inventory_update_detail', args=(self.pk,))
 
     def is_blocked_by(self, obj):
-        # FIXME: Block update when any other update is touching the same inventory!
-        # FIXME: Block update when any job is running using this inventory!
         if type(obj) == InventoryUpdate:
-            if self.inventory_source == obj.inventory_source:
+            if self.inventory_source.inventory == obj.inventory_source.inventory:
+                return True
+        if type(obj) == Job:
+            if self.inventory_source.inventory == obj.inventory:
                 return True
         return False
 
diff --git a/awx/main/models/jobs.py b/awx/main/models/jobs.py
index 87c5ec2f0a..25a5e4f0ce 100644
--- a/awx/main/models/jobs.py
+++ b/awx/main/models/jobs.py
@@ -256,9 +256,8 @@ class Job(UnifiedJob, JobOptions):
                 return True
             return False
         if type(obj) == InventoryUpdate:
-            for i_s in self.inventory.inventory_sources.filter(active=True):
-                if i_s == obj.inventory_source:
-                    return True
+            if self.inventory == obj.inventory_source.inventory:
+                return True
             return False
         if type(obj) == ProjectUpdate:
             if obj.project == self.project:
diff --git a/awx/main/models/projects.py b/awx/main/models/projects.py
index aa65d5153f..ecd94e21d2 100644
--- a/awx/main/models/projects.py
+++ b/awx/main/models/projects.py
@@ -334,10 +334,12 @@ class ProjectUpdate(UnifiedJob, ProjectOptions):
         return RunProjectUpdate
 
     def is_blocked_by(self, obj):
-        # FIXME: Block update when any job is running using this project!
         if type(obj) == ProjectUpdate:
             if self.project == obj.project:
                 return True
+        if type(obj) == Job:
+            if self.project == obj.project:
+                return True
         return False
 
     @property