diff --git a/flang/lib/Optimizer/Passes/Pipelines.cpp b/flang/lib/Optimizer/Passes/Pipelines.cpp
index 98f947a1f635d..6cc3290ff5cc2 100644
--- a/flang/lib/Optimizer/Passes/Pipelines.cpp
+++ b/flang/lib/Optimizer/Passes/Pipelines.cpp
@@ -14,7 +14,7 @@
 
 /// Force setting the no-alias attribute on fuction arguments when possible.
 static llvm::cl::opt<bool> forceNoAlias("force-no-alias", llvm::cl::Hidden,
-                                        llvm::cl::init(false));
+                                        llvm::cl::init(true));
 
 namespace fir {
 
diff --git a/flang/test/Driver/tco-test-gen.fir b/flang/test/Driver/tco-test-gen.fir
index 38d4e50ecf3aa..0bc8ed6ae4a11 100644
--- a/flang/test/Driver/tco-test-gen.fir
+++ b/flang/test/Driver/tco-test-gen.fir
@@ -1,8 +1,8 @@
-// RUN: tco -emit-final-mlir %s | FileCheck %s --check-prefixes=CHECK,AA,CMPLX
-// RUN: tco -emit-final-mlir -enable-aa=false %s | FileCheck %s --check-prefixes=CHECK,NOAA,CMPLX
-// RUN: tco -emit-final-mlir -simplify-mlir %s | FileCheck %s --check-prefixes=CHECK,AA,SIMPLE
-// RUN: tco -emit-final-mlir -enable-aa=false -simplify-mlir %s | FileCheck %s --check-prefixes=CHECK,NOAA,SIMPLE
-// RUN: tco -test-gen %s | FileCheck %s --check-prefixes=CHECK,NOAA,SIMPLE
+// RUN: tco -emit-final-mlir --force-no-alias=false %s | FileCheck %s --check-prefixes=CHECK,AA,CMPLX
+// RUN: tco -emit-final-mlir --force-no-alias=false -enable-aa=false %s | FileCheck %s --check-prefixes=CHECK,NOAA,CMPLX
+// RUN: tco -emit-final-mlir --force-no-alias=false -simplify-mlir %s | FileCheck %s --check-prefixes=CHECK,AA,SIMPLE
+// RUN: tco -emit-final-mlir --force-no-alias=false -enable-aa=false -simplify-mlir %s | FileCheck %s --check-prefixes=CHECK,NOAA,SIMPLE
+// RUN: tco -test-gen --force-no-alias=false %s | FileCheck %s --check-prefixes=CHECK,NOAA,SIMPLE
 
 // Just a dummy function that exhibits all of the things we want to turn on and off
 func.func @_QPtest(%arg0: !fir.ref<i32> {fir.bindc_name = "num"}, %arg1: !fir.ref<i32> {fir.bindc_name = "lb"}, %arg2: !fir.ref<i32> {fir.bindc_name = "ub"}, %arg3: !fir.ref<i32> {fir.bindc_name = "step"}) {
diff --git a/flang/test/Integration/cold_array_repacking.f90 b/flang/test/Integration/cold_array_repacking.f90
index 11b7d8c21b67f..2f5fe2bba21e7 100644
--- a/flang/test/Integration/cold_array_repacking.f90
+++ b/flang/test/Integration/cold_array_repacking.f90
@@ -1,6 +1,6 @@
 ! Check that the branch weights used by the array repacking
 ! are propagated all the way to LLVM IR:
-! RUN: %flang_fc1 -frepack-arrays -emit-llvm %s -o - | FileCheck %s
+! RUN: %flang_fc1 -frepack-arrays -mmlir --force-no-alias=false -emit-llvm %s -o - | FileCheck %s
 
 ! CHECK-LABEL: define void @test_(
 ! CHECK-SAME:      ptr [[TMP0:%.*]])
diff --git a/flang/test/Integration/complex-div-to-llvm-kind10.f90 b/flang/test/Integration/complex-div-to-llvm-kind10.f90
index 04d1f7ed9b024..5f7b070030f4b 100644
--- a/flang/test/Integration/complex-div-to-llvm-kind10.f90
+++ b/flang/test/Integration/complex-div-to-llvm-kind10.f90
@@ -1,8 +1,8 @@
 ! Test lowering complex division to llvm ir according to options
 
 ! REQUIRES: target=x86_64{{.*}}
-! RUN: %flang -fcomplex-arithmetic=improved -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,IMPRVD
-! RUN: %flang -fcomplex-arithmetic=basic -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,BASIC
+! RUN: %flang -fcomplex-arithmetic=improved -mmlir --force-no-alias=false -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,IMPRVD
+! RUN: %flang -fcomplex-arithmetic=basic -mmlir --force-no-alias=false -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,BASIC
 
 
 ! CHECK-LABEL: @div_test_extended
diff --git a/flang/test/Integration/complex-div-to-llvm.f90 b/flang/test/Integration/complex-div-to-llvm.f90
index 01782a565f24c..51342da3a2cee 100644
--- a/flang/test/Integration/complex-div-to-llvm.f90
+++ b/flang/test/Integration/complex-div-to-llvm.f90
@@ -1,7 +1,7 @@
 ! Test lowering complex division to llvm ir according to options
 
-! RUN: %flang -fcomplex-arithmetic=improved -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,IMPRVD
-! RUN: %flang -fcomplex-arithmetic=basic -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,BASIC
+! RUN: %flang -fcomplex-arithmetic=improved -mmlir --force-no-alias=false -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,IMPRVD
+! RUN: %flang -fcomplex-arithmetic=basic -mmlir --force-no-alias=false -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,BASIC
 
 
 ! CHECK-LABEL: @div_test_half
diff --git a/flang/test/Lower/OpenMP/target-data-skip-mapper-calls.f90 b/flang/test/Lower/OpenMP/target-data-skip-mapper-calls.f90
index f1a150d5dfabc..63ec8651e35b8 100644
--- a/flang/test/Lower/OpenMP/target-data-skip-mapper-calls.f90
+++ b/flang/test/Lower/OpenMP/target-data-skip-mapper-calls.f90
@@ -1,5 +1,5 @@
-!RUN: %flang_fc1 -emit-llvm -fopenmp %s -o - | FileCheck %s --check-prefix=NORT
-!RUN: %flang_fc1 -emit-llvm -fopenmp %s -o - | FileCheck %s --check-prefix=LLVM
+!RUN: %flang_fc1 -emit-llvm -fopenmp -mmlir --force-no-alias=false %s -o - | FileCheck %s --check-prefix=NORT
+!RUN: %flang_fc1 -emit-llvm -fopenmp -mmlir --force-no-alias=false %s -o - | FileCheck %s --check-prefix=LLVM
 
 !Make sure that there are no calls to the mapper.
 !NORT-NOT: call{{.*}}__tgt_target_data_begin_mapper