diff --git a/git-am.sh b/git-am.sh
index 6cdd5910db..b312da10d8 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -513,7 +513,8 @@ case "$resolved" in
 	'')
 		files=$(git ls-files) ;;
 	?*)
-		files=$(git diff-index --cached --name-only HEAD --) ;;
+		files=$(git diff-index --ignore-submodules --cached \
+			--name-only HEAD --) ;;
 	esac || exit
 	if test "$files"
 	then
@@ -682,7 +683,8 @@ do
 		case "$resolved$interactive" in
 		tt)
 			# This is used only for interactive view option.
-			git diff-index -p --cached HEAD -- >"$dotest/patch"
+			git diff-index --ignore-submodules -p --cached \
+				HEAD -- >"$dotest/patch"
 			;;
 		esac
 	esac
@@ -755,7 +757,7 @@ do
 		# trust what the user has in the index file and the
 		# working tree.
 		resolved=
-		git diff-index --quiet --cached HEAD -- && {
+		git diff-index --ignore-submodules --quiet --cached HEAD -- && {
 			echo "No changes - did you forget to use 'git add'?"
 			echo "If there is nothing left to stage, chances are that something else"
 			echo "already introduced the same changes; you might want to skip this patch."
@@ -779,7 +781,8 @@ do
 		then
 		    # Applying the patch to an earlier tree and merging the
 		    # result may have produced the same tree as ours.
-		    git diff-index --quiet --cached HEAD -- && {
+		    git diff-index --ignore-submodules --quiet --cached \
+				HEAD -- && {
 			say No changes -- Patch already applied.
 			go_next
 			continue