diff --git a/flang/lib/Lower/IntrinsicCall.cpp b/flang/lib/Lower/IntrinsicCall.cpp
--- a/flang/lib/Lower/IntrinsicCall.cpp
+++ b/flang/lib/Lower/IntrinsicCall.cpp
@@ -2527,19 +2527,16 @@
       assert(isStaticallyPresent(args[2]) &&
              "FPTR argument must be an array if SHAPE argument exists");
       mlir::Value shape = fir::getBase(args[2]);
-      mlir::Type shapeArrTy = fir::unwrapRefType(shape.getType());
-      auto arrayRank = shapeArrTy.cast<fir::SequenceType>().getShape()[0];
-      assert(arrayRank > 0 && arrayRank <= 15 &&
-             "The rank of array must have been known and in range 1-15");
-      for (int i = 0; i < (int)arrayRank; ++i) {
-        mlir::Value index =
-            builder.createIntegerConstant(loc, builder.getIntegerType(32), i);
+      int arrayRank = box.rank();
+      mlir::Type shapeElementType =
+          fir::unwrapSequenceType(fir::unwrapPassByRefType(shape.getType()));
+      mlir::Type idxType = builder.getIndexType();
+      for (int i = 0; i < arrayRank; ++i) {
+        mlir::Value index = builder.createIntegerConstant(loc, idxType, i);
         mlir::Value var = builder.create<fir::CoordinateOp>(
-            loc, builder.getRefType(fir::unwrapSequenceType(shapeArrTy)), shape,
-            index);
+            loc, builder.getRefType(shapeElementType), shape, index);
         mlir::Value load = builder.create<fir::LoadOp>(loc, var);
-        extents.push_back(
-            builder.createConvert(loc, builder.getIndexType(), load));
+        extents.push_back(builder.createConvert(loc, idxType, load));
       }
     }
     if (box.isCharacter()) {
diff --git a/flang/test/Lower/Intrinsics/c_f_pointer.f90 b/flang/test/Lower/Intrinsics/c_f_pointer.f90
--- a/flang/test/Lower/Intrinsics/c_f_pointer.f90
+++ b/flang/test/Lower/Intrinsics/c_f_pointer.f90
@@ -30,12 +30,12 @@
 ! CHECK:         %[[VAL_66:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_65]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
 ! CHECK:         %[[VAL_67:.*]] = fir.load %[[VAL_66]] : !fir.ref<i64>
 ! CHECK:         %[[VAL_68:.*]] = fir.convert %[[VAL_67]] : (i64) -> !fir.ptr<!fir.array<?x?xf32>>
-! CHECK:         %[[VAL_69:.*]] = arith.constant 0 : i32
-! CHECK:         %[[VAL_70:.*]] = fir.coordinate_of %[[VAL_53:.*]], %[[VAL_69]] : (!fir.heap<!fir.array<2xi32>>, i32) -> !fir.ref<i32>
+! CHECK:         %[[VAL_69:.*]] = arith.constant 0 : index
+! CHECK:         %[[VAL_70:.*]] = fir.coordinate_of %[[VAL_53:.*]], %[[VAL_69]] : (!fir.heap<!fir.array<2xi32>>, index) -> !fir.ref<i32>
 ! CHECK:         %[[VAL_71:.*]] = fir.load %[[VAL_70]] : !fir.ref<i32>
 ! CHECK:         %[[VAL_72:.*]] = fir.convert %[[VAL_71]] : (i32) -> index
-! CHECK:         %[[VAL_73:.*]] = arith.constant 1 : i32
-! CHECK:         %[[VAL_74:.*]] = fir.coordinate_of %[[VAL_53]], %[[VAL_73]] : (!fir.heap<!fir.array<2xi32>>, i32) -> !fir.ref<i32>
+! CHECK:         %[[VAL_73:.*]] = arith.constant 1 : index
+! CHECK:         %[[VAL_74:.*]] = fir.coordinate_of %[[VAL_53]], %[[VAL_73]] : (!fir.heap<!fir.array<2xi32>>, index) -> !fir.ref<i32>
 ! CHECK:         %[[VAL_75:.*]] = fir.load %[[VAL_74]] : !fir.ref<i32>
 ! CHECK:         %[[VAL_76:.*]] = fir.convert %[[VAL_75]] : (i32) -> index
 ! CHECK:         %[[VAL_77:.*]] = fir.shape %[[VAL_72]], %[[VAL_76]] : (index, index) -> !fir.shape<2>
@@ -85,12 +85,12 @@
 ! CHECK:         %[[VAL_71:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_70]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
 ! CHECK:         %[[VAL_72:.*]] = fir.load %[[VAL_71]] : !fir.ref<i64>
 ! CHECK:         %[[VAL_73:.*]] = fir.convert %[[VAL_72]] : (i64) -> !fir.ptr<!fir.array<?x?x!fir.char<1,?>>>
-! CHECK:         %[[VAL_74:.*]] = arith.constant 0 : i32
-! CHECK:         %[[VAL_75:.*]] = fir.coordinate_of %[[VAL_58:.*]], %[[VAL_74]] : (!fir.heap<!fir.array<2xi32>>, i32) -> !fir.ref<i32>
+! CHECK:         %[[VAL_74:.*]] = arith.constant 0 : index
+! CHECK:         %[[VAL_75:.*]] = fir.coordinate_of %[[VAL_58:.*]], %[[VAL_74]] : (!fir.heap<!fir.array<2xi32>>, index) -> !fir.ref<i32>
 ! CHECK:         %[[VAL_76:.*]] = fir.load %[[VAL_75]] : !fir.ref<i32>
 ! CHECK:         %[[VAL_77:.*]] = fir.convert %[[VAL_76]] : (i32) -> index
-! CHECK:         %[[VAL_78:.*]] = arith.constant 1 : i32
-! CHECK:         %[[VAL_79:.*]] = fir.coordinate_of %[[VAL_58]], %[[VAL_78]] : (!fir.heap<!fir.array<2xi32>>, i32) -> !fir.ref<i32>
+! CHECK:         %[[VAL_78:.*]] = arith.constant 1 : index
+! CHECK:         %[[VAL_79:.*]] = fir.coordinate_of %[[VAL_58]], %[[VAL_78]] : (!fir.heap<!fir.array<2xi32>>, index) -> !fir.ref<i32>
 ! CHECK:         %[[VAL_80:.*]] = fir.load %[[VAL_79]] : !fir.ref<i32>
 ! CHECK:         %[[VAL_81:.*]] = fir.convert %[[VAL_80]] : (i32) -> index
 ! CHECK:         %[[VAL_82:.*]] = fir.shape %[[VAL_77]], %[[VAL_81]] : (index, index) -> !fir.shape<2>
@@ -107,3 +107,41 @@
 
   call c_f_pointer(cptr, fptr, [x, y])
 end
+
+! CHECK-LABEL: func.func @_QPdynamic_shape_size(
+subroutine dynamic_shape_size(cptr, fptr, shape)                             
+  use iso_c_binding
+  type(c_ptr)  :: cptr                            
+  real, pointer :: fptr(:, :)                                
+  integer :: shape(:)                                     
+! CHECK:         %[[VAL_7:.*]] = arith.constant 0 : index
+! CHECK:         %[[VAL_8:.*]] = fir.coordinate_of %[[VAL_2]], %[[VAL_7]] : (!fir.box<!fir.array<?xi32>>, index) -> !fir.ref<i32>
+! CHECK:         %[[VAL_9:.*]] = fir.load %[[VAL_8]] : !fir.ref<i32>
+! CHECK:         %[[VAL_10:.*]] = fir.convert %[[VAL_9]] : (i32) -> index
+! CHECK:         %[[VAL_11:.*]] = arith.constant 1 : index
+! CHECK:         %[[VAL_12:.*]] = fir.coordinate_of %[[VAL_2]], %[[VAL_11]] : (!fir.box<!fir.array<?xi32>>, index) -> !fir.ref<i32>
+! CHECK:         %[[VAL_13:.*]] = fir.load %[[VAL_12]] : !fir.ref<i32>
+! CHECK:         %[[VAL_14:.*]] = fir.convert %[[VAL_13]] : (i32) -> index
+! CHECK:         %[[VAL_15:.*]] = fir.shape %[[VAL_10]], %[[VAL_14]] : (index, index) -> !fir.shape<2>
+  call c_f_pointer(cptr, fptr, shape)
+end subroutine      
+
+! CHECK-LABEL: func.func @_QPdynamic_shape_size_2(
+subroutine dynamic_shape_size_2(cptr, fptr, shape, n)                                          
+  use iso_c_binding                                                                            
+  type(c_ptr)  :: cptr                                                                         
+  real, pointer :: fptr(:, :) 
+  integer :: n
+  integer :: shape(n)
+! CHECK:         %[[VAL_8:.*]] = arith.constant 0 : index
+! CHECK:         %[[VAL_9:.*]] = fir.coordinate_of %[[VAL_2]], %[[VAL_8]] : (!fir.ref<!fir.array<?xi32>>, index) -> !fir.ref<i32>
+! CHECK:         %[[VAL_10:.*]] = fir.load %[[VAL_9]] : !fir.ref<i32>
+! CHECK:         %[[VAL_11:.*]] = fir.convert %[[VAL_10]] : (i32) -> index
+! CHECK:         %[[VAL_12:.*]] = arith.constant 1 : index
+! CHECK:         %[[VAL_13:.*]] = fir.coordinate_of %[[VAL_2]], %[[VAL_12]] : (!fir.ref<!fir.array<?xi32>>, index) -> !fir.ref<i32>
+! CHECK:         %[[VAL_14:.*]] = fir.load %[[VAL_13]] : !fir.ref<i32>
+! CHECK:         %[[VAL_15:.*]] = fir.convert %[[VAL_14]] : (i32) -> index
+! CHECK:         %[[VAL_16:.*]] = fir.shape %[[VAL_11]], %[[VAL_15]] : (index, index) -> !fir.shape<2>
+  call c_f_pointer(cptr, fptr, shape)
+end subroutine
+