diff --git a/app/helpers/gallery_helper.rb b/app/helpers/gallery_helper.rb
index 1f9ddeeab..89e27842e 100644
--- a/app/helpers/gallery_helper.rb
+++ b/app/helpers/gallery_helper.rb
@@ -8,19 +8,22 @@ module GalleryHelper
   end
 
   def preview_url_for(attachment)
-    attachment.preview(resize_to_limit: [400, 400]).processed.url
+    preview = attachment.preview(resize_to_limit: [400, 400])
+    preview.image.attached? ? preview.processed.url : 'pdf-placeholder.png'
   rescue StandardError
     'pdf-placeholder.png'
   end
 
   def variant_url_for(attachment)
-    attachment.variant(resize_to_limit: [400, 400]).processed.url
+    variant = attachment.variant(resize_to_limit: [400, 400])
+    variant.key.present? ? variant.processed.url : 'apercu-indisponible.png'
   rescue StandardError
     'apercu-indisponible.png'
   end
 
   def blob_url(attachment)
-    attachment.blob.content_type.in?(RARE_IMAGE_TYPES) ? attachment.variant(resize_to_limit: [2000, 2000]).processed.url : attachment.blob.url
+    variant = attachment.variant(resize_to_limit: [2000, 2000])
+    attachment.blob.content_type.in?(RARE_IMAGE_TYPES) && variant.key.present? ? variant.processed.url : attachment.blob.url
   rescue StandardError
     attachment.blob.url
   end
diff --git a/spec/helpers/gallery_helper_spec.rb b/spec/helpers/gallery_helper_spec.rb
index 41469798c..22ddabd32 100644
--- a/spec/helpers/gallery_helper_spec.rb
+++ b/spec/helpers/gallery_helper_spec.rb
@@ -22,13 +22,21 @@ RSpec.describe GalleryHelper, type: :helper do
   describe ".variant_url_for" do
     subject { variant_url_for(attachment) }
 
-    context "when attachment can be represented with a variant" do
+    context "when image attachment has a variant" do
       let(:file) { fixture_file_upload('spec/fixtures/files/logo_test_procedure.png', 'image/png') }
 
-      it { expect { subject }.to change { ActiveStorage::VariantRecord.count }.by(1) }
+      before { attachment.variant(resize_to_limit: [400, 400]).processed }
+
       it { is_expected.not_to eq("apercu-indisponible.png") }
     end
 
+    context "when image attachment has no variant" do
+      let(:file) { fixture_file_upload('spec/fixtures/files/logo_test_procedure.png', 'image/png') }
+
+      it { expect { subject }.not_to change { ActiveStorage::VariantRecord.count } }
+      it { is_expected.to eq("apercu-indisponible.png") }
+    end
+
     context "when attachment cannot be represented with a variant" do
       let(:file) { fixture_file_upload('spec/fixtures/files/instructeurs-file.csv', 'text/csv') }
 
@@ -40,13 +48,21 @@ RSpec.describe GalleryHelper, type: :helper do
   describe ".preview_url_for" do
     subject { preview_url_for(attachment) }
 
-    context "when attachment can be represented with a preview" do
+    context "when pdf attachment has a preview" do
       let(:file) { fixture_file_upload('spec/fixtures/files/RIB.pdf', 'application/pdf') }
 
-      it { expect { subject }.to change { ActiveStorage::VariantRecord.count }.by(1) }
+      before { attachment.preview(resize_to_limit: [400, 400]).processed }
+
       it { is_expected.not_to eq("pdf-placeholder.png") }
     end
 
+    context "when pdf attachment has no preview" do
+      let(:file) { fixture_file_upload('spec/fixtures/files/RIB.pdf', 'application/pdf') }
+
+      it { expect { subject }.not_to change { ActiveStorage::VariantRecord.count } }
+      it { is_expected.to eq("pdf-placeholder.png") }
+    end
+
     context "when attachment cannot be represented with a preview" do
       let(:file) { fixture_file_upload('spec/fixtures/files/instructeurs-file.csv', 'text/csv') }