diff --git a/flang/include/flang/Tools/CLOptions.inc b/flang/include/flang/Tools/CLOptions.inc
--- a/flang/include/flang/Tools/CLOptions.inc
+++ b/flang/include/flang/Tools/CLOptions.inc
@@ -29,8 +29,8 @@
 /// allocations should always be on the heap.
 static llvm::cl::opt<bool> dynamicArrayStackToHeapAllocation(
     "fdynamic-heap-array",
-    llvm::cl::desc("place all array allocations of dynamic size on the heap"),
-    llvm::cl::init(false), llvm::cl::Hidden);
+    llvm::cl::desc("place all array allocations of fully dynamic size on the heap"),
+    llvm::cl::init(true), llvm::cl::Hidden);
 
 /// Shared option in tools to set a maximum value for the number of elements in
 /// a compile-time sized array that can be allocated on the stack.
diff --git a/flang/lib/Optimizer/Transforms/MemoryAllocation.cpp b/flang/lib/Optimizer/Transforms/MemoryAllocation.cpp
--- a/flang/lib/Optimizer/Transforms/MemoryAllocation.cpp
+++ b/flang/lib/Optimizer/Transforms/MemoryAllocation.cpp
@@ -78,8 +78,15 @@
   if (auto seqTy = alloca.getInType().dyn_cast<fir::SequenceType>()) {
     if (fir::hasDynamicSize(seqTy)) {
       // Move all arrays with runtime determined size to the heap.
-      if (options.dynamicArrayOnHeap)
+      if (options.dynamicArrayOnHeap) {
+        for (const auto d : seqTy.getShape()) {
+          // Keep array on stack if some of the dimensions are static
+          if (d != seqTy.getUnknownExtent())
+            return true;
+        }
+        // move to heap otherwise
         return false;
+      }
     } else {
       std::int64_t numberOfElements = 1;
       for (std::int64_t i : seqTy.getShape()) {
diff --git a/flang/test/Fir/alloc.fir b/flang/test/Fir/alloc.fir
--- a/flang/test/Fir/alloc.fir
+++ b/flang/test/Fir/alloc.fir
@@ -1,5 +1,4 @@
-// RUN: tco %s | FileCheck %s
-// RUN: %flang_fc1 -emit-llvm  %s -o - | FileCheck %s
+// RUN: %flang_fc1 -mllvm -fdynamic-heap-array=false -emit-llvm  %s -o - | FileCheck %s
 
 // UNSUPPORTED: system-windows
 
diff --git a/flang/test/Lower/array-stack.f90 b/flang/test/Lower/array-stack.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/array-stack.f90
@@ -0,0 +1,17 @@
+! Tests moving stack allocated dynamic arrays with all dynamic dimensions to heap
+! RUN: bbc %s -o - | FileCheck %s
+
+! CHECK-LABEL:  func @_QPss2(
+! CHECK: %[[A:.*]] = fir.alloca !fir.array<5xf32> {bindc_name = "a", uniq_name = "{{.*}}Ea"}
+! CHECK: %[[B:.*]] = fir.allocmem !fir.array<?xf32>, %4 {bindc_name = "b", uniq_name = "{{.*}}Eb"}
+! CHECK: %[[C:.*]] = fir.allocmem !fir.array<?x?xi32>, %4, %4 {bindc_name = "c", uniq_name = "{{.*}}Ec"}
+! CHECK: %[[D:.*]] = fir.alloca !fir.array<5x?x?xi32>, %4, %4 {bindc_name = "d", uniq_name = "{{.*}}Ed"}
+! CHECK: fir.freemem %[[B]] : !fir.heap<!fir.array<?xf32>>
+! CHECK: fir.freemem %[[C]] : !fir.heap<!fir.array<?x?xi32>>
+
+subroutine ss2(N)
+  real :: A(5)
+  real :: B(N)
+  integer :: C(N,N)
+  integer :: D(5,N,N)
+end
diff --git a/flang/test/Lower/array-temp.f90 b/flang/test/Lower/array-temp.f90
--- a/flang/test/Lower/array-temp.f90
+++ b/flang/test/Lower/array-temp.f90
@@ -1,4 +1,4 @@
-! RUN: bbc %s -o - | FileCheck %s
+! RUN: bbc %s -fdynamic-heap-array=false -o - | FileCheck %s
 
 ! CHECK-LABEL: func @_QPss1()
 subroutine ss1
diff --git a/flang/test/Lower/character-local-variables.f90 b/flang/test/Lower/character-local-variables.f90
--- a/flang/test/Lower/character-local-variables.f90
+++ b/flang/test/Lower/character-local-variables.f90
@@ -1,4 +1,4 @@
-! RUN: bbc %s -o - | FileCheck %s
+! RUN: bbc %s -fdynamic-heap-array=false -o - | FileCheck %s
 
 ! Test lowering of local character variables
 
diff --git a/flang/test/Lower/explicit-interface-results-2.f90 b/flang/test/Lower/explicit-interface-results-2.f90
--- a/flang/test/Lower/explicit-interface-results-2.f90
+++ b/flang/test/Lower/explicit-interface-results-2.f90
@@ -1,7 +1,7 @@
 ! Test lowering of internal procedures returning arrays or characters.
 ! This test allocation on the caller side of the results that may depend on
 ! host associated symbols.
-! RUN: bbc %s -o - | FileCheck %s
+! RUN: bbc %s -fdynamic-heap-array=false -o - | FileCheck %s
 
 module some_module
  integer :: n_module