diff --git a/mlir/lib/IR/Diagnostics.cpp b/mlir/lib/IR/Diagnostics.cpp
--- a/mlir/lib/IR/Diagnostics.cpp
+++ b/mlir/lib/IR/Diagnostics.cpp
@@ -466,7 +466,7 @@
   SmallVector<std::pair<Location, StringRef>> locationStack;
   auto addLocToStack = [&](Location loc, StringRef locContext) {
     if (Optional<Location> showableLoc = findLocToShow(loc))
-      locationStack.emplace_back(loc, locContext);
+      locationStack.emplace_back(showableLoc.getValue(), locContext);
   };
 
   // Add locations to display for this diagnostic.
@@ -489,7 +489,9 @@
 
   // If the location stack is empty, use the initial location.
   if (locationStack.empty()) {
-    emitDiagnostic(diag.getLocation(), diag.str(), diag.getSeverity());
+    if (Optional<Location> showableLoc = findLocToShow(diag.getLocation())) {
+      emitDiagnostic(showableLoc.getValue(), diag.str(), diag.getSeverity());
+    }
 
     // Otherwise, use the location stack.
   } else {
diff --git a/mlir/test/IR/diagnostic-handler-filter.mlir b/mlir/test/IR/diagnostic-handler-filter.mlir
--- a/mlir/test/IR/diagnostic-handler-filter.mlir
+++ b/mlir/test/IR/diagnostic-handler-filter.mlir
@@ -11,7 +11,7 @@
 // -----
 
 // CHECK-LABEL: Test 'test2'
-// CHECK-NEXT: mysource1:0:0: error: test diagnostic
+// CHECK-NOT: mysource1:0:0: error: test diagnostic
 func private @test2() attributes {
   test.loc = loc("mysource1":0:0)
 }