diff --git a/go/cmd/dolt/commands/diff.go b/go/cmd/dolt/commands/diff.go
index 3e11882254..10ed748366 100644
--- a/go/cmd/dolt/commands/diff.go
+++ b/go/cmd/dolt/commands/diff.go
@@ -875,7 +875,7 @@ func createSplitter(ctx context.Context, vrw types.ValueReadWriter, fromSch sche
 
 		unionSch, err = untyped.UntypedSchemaUnion(dumbNewSch, dumbOldSch)
 		if err != nil {
-			return nil, nil, errhand.BuildDError("Cannot merge schemas with different primary key sets").AddCause(err).Build()
+			return nil, nil, errhand.BuildDError("Merge failed. Tables with different primary keys cannot be merged.").AddCause(err).Build()
 		}
 
 	} else {
diff --git a/integration-tests/bats/schema-changes.bats b/integration-tests/bats/schema-changes.bats
index ce0f6c6409..1f0c00e35c 100755
--- a/integration-tests/bats/schema-changes.bats
+++ b/integration-tests/bats/schema-changes.bats
@@ -32,7 +32,7 @@ teardown() {
     [ "$status" -eq 0 ]
     [[ "$output" =~ "BIGINT" ]] || false
     [[ "$output" =~ "LONGTEXT" ]] || false
-    [[ ! "$ouput" =~ "Cannot merge schemas with different primary key sets" ]] || false
+    [[ ! "$ouput" =~ "Merge failed" ]] || false
 }
 
 @test "schema-changes: dolt schema rename column" {