diff --git a/meson.build b/meson.build
index e94d07e70f8..a731147298c 100644
--- a/meson.build
+++ b/meson.build
@@ -8,7 +8,7 @@ project(
     'b_vscrt=static_from_buildtype', # Link runtime libraries statically on Windows
     'optimization=2',
     'debug=false',
-    'fortran_std=f2008',
+    'fortran_std=f2018',
 ])
 
 if get_option('optimization') == '3'
diff --git a/pymake/makedefaults b/pymake/makedefaults
index c8249886793..a90a6cf8a66 100644
--- a/pymake/makedefaults
+++ b/pymake/makedefaults
@@ -58,11 +58,11 @@ OPTLEVEL ?= -O2
 # set the fortran flags
 ifeq ($(detected_OS), Windows)
 	ifeq ($(FC), gfortran)
-		FFLAGS ?= -static -fbacktrace -ffpe-summary=overflow -ffpe-trap=overflow,zero,invalid $(OS_macro) -Wtabs -Wline-truncation -Wunused-label -Wunused-variable -pedantic -std=f2008 -Wcharacter-truncation -cpp
+		FFLAGS ?= -static -fbacktrace -ffpe-summary=overflow -ffpe-trap=overflow,zero,invalid $(OS_macro) -Wtabs -Wline-truncation -Wunused-label -Wunused-variable -pedantic -std=f2018 -Wcharacter-truncation -cpp
 	endif
 else
 	ifeq ($(FC), gfortran)
-		FFLAGS ?= -fbacktrace -ffpe-summary=overflow -ffpe-trap=overflow,zero,invalid $(OS_macro) -Wtabs -Wline-truncation -Wunused-label -Wunused-variable -pedantic -std=f2008 -Wcharacter-truncation -cpp
+		FFLAGS ?= -fbacktrace -ffpe-summary=overflow -ffpe-trap=overflow,zero,invalid $(OS_macro) -Wtabs -Wline-truncation -Wunused-label -Wunused-variable -pedantic -std=f2018 -Wcharacter-truncation -cpp
 	endif
 	ifeq ($(FC), $(filter $(FC), ifort mpiifort))
 		FFLAGS ?= -no-heap-arrays -fpe0 -traceback -fpp
diff --git a/src/Solution/LinearMethods/ImsReordering.f90 b/src/Solution/LinearMethods/ImsReordering.f90
index 7b4138ff0d7..81b5bfa6bba 100644
--- a/src/Solution/LinearMethods/ImsReordering.f90
+++ b/src/Solution/LinearMethods/ImsReordering.f90
@@ -300,12 +300,13 @@ subroutine ims_md(n, nja, ia, ja, mmax, v, l, head, last, next, &
     ! -- local
     integer(I4B) :: tag
     integer(I4B) :: dmin
-    integer(I4B) :: vk
-    integer(I4B) :: ek
+    integer(I4B), pointer :: vk
+    integer(I4B), pointer :: ek
     integer(I4B) :: tail
     integer(I4B) :: k
 
-    equivalence(vk, ek)
+    allocate (vk)
+    ek => vk
     !
     ! initialization
     tag = 0
@@ -353,6 +354,8 @@ subroutine ims_md(n, nja, ia, ja, mmax, v, l, head, last, next, &
       last(next(k)) = k
     end do
     !
+    deallocate (vk)
+    !
     return
   end subroutine ims_md
 
@@ -482,15 +485,16 @@ subroutine ims_mdm(n, mmax, vk, tail, v, l, last, next, mark)
     integer(I4B) :: tag
     integer(I4B) :: s
     integer(I4B) :: ls
-    integer(I4B) :: vs
-    integer(I4B) :: es
+    integer(I4B), pointer :: vs
+    integer(I4B), pointer :: es
     integer(I4B) :: b
     integer(I4B) :: lb
     integer(I4B) :: vb
     integer(I4B) :: blp
     integer(I4B) :: blpmax
 
-    equivalence(vs, es)
+    allocate (vs)
+    es => vs
     !
     ! initialize tag and list of uneliminated neighbors
     tag = mark(vk)
@@ -535,6 +539,8 @@ subroutine ims_mdm(n, mmax, vk, tail, v, l, last, next, mark)
     !
     ! terminate list of uneliminated neighbors
 5   l(tail) = 0
+    !
+    deallocate (vs)
     !
     return
   end subroutine ims_mdm
@@ -681,8 +687,8 @@ subroutine ims_mdu(n, mmax, ek, dmin, v, l, head, last, next, mark)
     integer(I4B) :: evi
     integer(I4B) :: dvi
     integer(I4B) :: s
-    integer(I4B) :: vs
-    integer(I4B) :: es
+    integer(I4B), pointer :: vs
+    integer(I4B), pointer :: es
     integer(I4B) :: b
     integer(I4B) :: vb
     integer(I4B) :: ilp
@@ -691,7 +697,8 @@ subroutine ims_mdu(n, mmax, ek, dmin, v, l, head, last, next, mark)
     integer(I4B) :: blpmax
     integer(I4B) :: i
 
-    equivalence(vs, es)
+    allocate (vs)
+    es => vs
     !
     ! initialize tag
     tag = mark(ek) - last(ek)
@@ -768,7 +775,9 @@ subroutine ims_mdu(n, mmax, ek, dmin, v, l, head, last, next, mark)
       !
     end do louter !10
     !
-11  return
+11  deallocate (vs)
+    !
+    return
   end subroutine ims_mdu
 
 end module IMSReorderingModule