diff --git a/Makefile b/Makefile
index 1250ae88..baca3e04 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ SOURCE_VER ?= v0.15.4
 REFLECTOR_VER ?= v0.11.1
 
 # Version of libgit2 the controller should depend on.
-LIBGIT2_VER ?= 1.2.0
+LIBGIT2_VER ?= 1.1.1
 
 # Repository root based on Git metadata.
 REPOSITORY_ROOT := $(shell git rev-parse --show-toplevel)
diff --git a/controllers/imageupdateautomation_controller.go b/controllers/imageupdateautomation_controller.go
index f029aadc..5e5eae8b 100644
--- a/controllers/imageupdateautomation_controller.go
+++ b/controllers/imageupdateautomation_controller.go
@@ -30,7 +30,7 @@ import (
 	"time"
 
 	gogit "github.com/go-git/go-git/v5"
-	libgit2 "github.com/libgit2/git2go/v32"
+	libgit2 "github.com/libgit2/git2go/v31"
 
 	"github.com/ProtonMail/go-crypto/openpgp"
 	securejoin "github.com/cyphar/filepath-securejoin"
@@ -680,11 +680,11 @@ func push(ctx context.Context, path, branch string, access repoAccess) error {
 	// calling repo.Push will succeed even if a reference update is
 	// rejected; to detect this case, this callback is supplied.
 	var callbackErr error
-	callbacks.PushUpdateReferenceCallback = func(refname, status string) error {
+	callbacks.PushUpdateReferenceCallback = func(refname, status string) libgit2.ErrorCode {
 		if status != "" {
 			callbackErr = fmt.Errorf("ref %s rejected: %s", refname, status)
 		}
-		return nil
+		return libgit2.ErrorCodeOK
 	}
 	err = origin.Push([]string{fmt.Sprintf("refs/heads/%s:refs/heads/%s", branch, branch)}, &libgit2.PushOptions{
 		RemoteCallbacks: callbacks,
diff --git a/go.mod b/go.mod
index 89a1ea2e..8e050e0a 100644
--- a/go.mod
+++ b/go.mod
@@ -16,13 +16,13 @@ require (
 	github.com/fluxcd/pkg/ssh v0.1.0
 	// If you bump this, change SOURCE_VER in the Makefile to match
 	// TODO(hidde): set to tagged version of release.
-	github.com/fluxcd/source-controller v0.15.5-0.20210928151156-c03db6234dcd
+	github.com/fluxcd/source-controller v0.15.5-0.20210930103634-ac1b95090415
 	github.com/fluxcd/source-controller/api v0.15.4
 	github.com/go-git/go-billy/v5 v5.3.1
 	github.com/go-git/go-git/v5 v5.4.2
 	github.com/go-logr/logr v0.4.0
 	github.com/google/go-containerregistry v0.6.0
-	github.com/libgit2/git2go/v32 v32.0.4
+	github.com/libgit2/git2go/v31 v31.6.1
 	github.com/onsi/ginkgo v1.16.4
 	github.com/onsi/gomega v1.14.0
 	github.com/otiai10/copy v1.2.0
diff --git a/go.sum b/go.sum
index c201c5b2..d87982fd 100644
--- a/go.sum
+++ b/go.sum
@@ -356,8 +356,8 @@ github.com/fluxcd/pkg/testserver v0.1.0/go.mod h1:fvt8BHhXw6c1+CLw1QFZxcQprlcXzs
 github.com/fluxcd/pkg/untar v0.1.0/go.mod h1:aGswNyzB1mlz/T/kpOS58mITBMxMKc9tlJBH037A2HY=
 github.com/fluxcd/pkg/version v0.1.0 h1:v+SmCanmCB5Tj2Cx9TXlj+kNRfPGbAvirkeqsp7ZEAQ=
 github.com/fluxcd/pkg/version v0.1.0/go.mod h1:V7Z/w8dxLQzv0FHqa5ox5TeyOd2zOd49EeuWFgnwyj4=
-github.com/fluxcd/source-controller v0.15.5-0.20210928151156-c03db6234dcd h1:vZFbBEyr74+2lcHjaXrIf7xVSQDjczCwcM8pFgvKgfQ=
-github.com/fluxcd/source-controller v0.15.5-0.20210928151156-c03db6234dcd/go.mod h1:YBJOjXLklT3QthsUDpPo+Y1Hec3xvbvA6emIG8FjDYQ=
+github.com/fluxcd/source-controller v0.15.5-0.20210930103634-ac1b95090415 h1:XrTvVFkWdFQX6GbosGNVtfreqAVqjBtFVk2cqy0uBYk=
+github.com/fluxcd/source-controller v0.15.5-0.20210930103634-ac1b95090415/go.mod h1:XPuJVVTs4eYwDWbZjaZY6JLiaNMPti+sl6LpCewEcvc=
 github.com/fluxcd/source-controller/api v0.15.4 h1:9aRcH/WKJWt7Bp954K/wzLRuiRiHuD2osvYp74GoP64=
 github.com/fluxcd/source-controller/api v0.15.4/go.mod h1:guUCCapjzE2kocwFreQTM/IGvtAglIJc4L97mokairo=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
@@ -681,8 +681,8 @@ github.com/lann/builder v0.0.0-20180802200727-47ae307949d0/go.mod h1:dXGbAdH5GtB
 github.com/lann/ps v0.0.0-20150810152359-62de8c46ede0/go.mod h1:vmVJ0l/dxyfGW6FmdpVm2joNMFikkuWg0EoCKLGUMNw=
 github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.10.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
-github.com/libgit2/git2go/v32 v32.0.4 h1:qK2yWGh88K2Gh76E1+vUEsjKDfOAq0J2THKaoaFIPbA=
-github.com/libgit2/git2go/v32 v32.0.4/go.mod h1:FAA2ePV5PlLjw1ccncFIvu2v8hJSZVN5IzEn4lo/vwo=
+github.com/libgit2/git2go/v31 v31.6.1 h1:FnKHHDDBgltSsu9RpKuL4rSR8dQ1JTf9dfvFhZ1y7Aw=
+github.com/libgit2/git2go/v31 v31.6.1/go.mod h1:c/rkJcBcUFx6wHaT++UwNpKvIsmPNqCeQ/vzO4DrEec=
 github.com/liggitt/tabwriter v0.0.0-20181228230101-89fcab3d43de/go.mod h1:zAbeS9B/r2mtpb6U+EI2rYA5OAXxsYw6wTamcNW+zcE=
 github.com/lightstep/lightstep-tracer-common/golang/gogo v0.0.0-20190605223551-bc2310a04743/go.mod h1:qklhhLq1aX+mtWk9cPHPzaBjWImj5ULL6C7HFJtXQMM=
 github.com/lightstep/lightstep-tracer-go v0.18.1/go.mod h1:jlF1pusYV4pidLvZ+XD0UBX0ZE6WURAspgAczcDHrL4=