Index: /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-solid_earth-static.sh
===================================================================
--- /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-solid_earth-static.sh	(revision 25611)
+++ /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-solid_earth-static.sh	(revision 25612)
@@ -4,8 +4,9 @@
 
 # NOTE: There is a single difference between the Linux and macOS 
-#		configurations, which is the addition of the -static-libgfortran 
-#		option to FFLAGS on the macOS static configurations. For the sake of 
-#		consistency, we maintain separate files for each, respective Linux and 
-#		macOS configuration.
+#		configurations, which is the addition of the -fallow-argument-mismatch 
+#		and -static-libgfortran options to FFLAGS on the macOS static 
+#		configurations. For the sake of consistency, we maintain separate files 
+#		for each, respective Linux and macOS configuration.
+#
 
 ## Constants
Index: /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-solid_earth.sh
===================================================================
--- /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-solid_earth.sh	(revision 25611)
+++ /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-solid_earth.sh	(revision 25612)
@@ -32,4 +32,5 @@
 	--prefix="${ISSM_DIR}/externalpackages/petsc/install" \
 	--PETSC_DIR="${ISSM_DIR}/externalpackages/petsc/src" \
+	--FFLAGS="-fallow-argument-mismatch" \
 	--with-debugging=0 \
 	--with-valgrind=0 \
Index: /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-static.sh
===================================================================
--- /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-static.sh	(revision 25611)
+++ /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac-static.sh	(revision 25612)
@@ -4,8 +4,9 @@
 
 # NOTE: There is a single difference between the Linux and macOS 
-#		configurations, which is the addition of the -static-libgfortran 
-#		option to FFLAGS on the macOS static configurations. For the sake of 
-#		consistency, we maintain separate files for each, respective Linux and 
-#		macOS configuration.
+#		configurations, which is the addition of the -fallow-argument-mismatch 
+#		and -static-libgfortran options to FFLAGS on the macOS static 
+#		configurations. For the sake of consistency, we maintain separate files 
+#		for each, respective Linux and macOS configuration.
+#
 
 ## Constants
Index: /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac.sh
===================================================================
--- /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac.sh	(revision 25611)
+++ /issm/trunk-jpl/externalpackages/petsc/install-3.12-mac.sh	(revision 25612)
@@ -32,4 +32,5 @@
 	--prefix="${ISSM_DIR}/externalpackages/petsc/install" \
 	--PETSC_DIR="${ISSM_DIR}/externalpackages/petsc/src" \
+	--FFLAGS="-fallow-argument-mismatch" \
 	--with-debugging=0 \
 	--with-valgrind=0 \